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1 INTRODUCTION Aortic stenosis is a condition in which the valve does not open completely, blocking the ejection path of the left ventricle Cardiovascular disease ranks 3rd after hypertension and coronary artery disease, with a frequency of - 7% Up to now, the assessment of the aortic valve has always been considered the most difficult of the heart valves, but thanks to the advancement of diagnostic tools and the aging of the population, aortic stenosis is becoming more common The disease usually progresses silently, when symptoms appear, the prognosis is severe with a 2-year mortality rate of up to 50% In European and American countries, aortic valve replacement surgery has a history of more than 50 years, so far there are many surgical treatment methods In addition to the obvious survival benefit, structural and functional abnormalities of the left ventricle as well as the clinical status were markedly improved after aortic valve replacement This change has been confirmed by many studies, but most of the authors evaluated it at months to year or even longer after surgery, very few authors studied the pathology or described in this study multiple time points periodically monitor and compare pairs at different time points In order to contribute more scientific evidence in the diagnosis, selection of treatment methods and monitoring of postoperative outcomes for aortic stenosis, we conducted this study to: Comment on clinical and subclinical characteristics of patients with aortic valve stenosis undergoing aortic valve replacement surgery at Military Central Hospital 108 Evaluation of early and medium-term results of valve replacement surgery for aortic stenosis at Military Central Hospital 108 2 CONTRIBUTIONS OF THE THESIS - The results of the study further diversify the research results on clinical, subclinical and histopathological characteristics of aortic stenosis undergoing valve replacement, contributing to its application to the clinical practice of cardiovascular disease in our country - The study provided basic information on the results of valve replacement surgery, especially the variation of left ventricle and PPM as well as related factors through pairwise comparison at 108 Central Hospital THESIS STRUCTURE The thesis consists of 138 pages (excluding appendices and references), including main chapters: Introduction: pages, chapter – Overview: 38 pages, chapter - Objects and study methodology: 25 pages, chapter – Findings: 33 pages, chapter – Discussion: 36 pages, conclusions and recommendations: pages The thesis has 44 tables, 32 charts, 14 illustrations, diagram, 148 references, including 17 Vietnamese documents and 131 English documents CHAPTER 1: LITERATURA REVIEW 1.1 Anatomical features, pathophysiology, pathology of AS 1.1.1 Applied surgical anatomy of the aortic valve The aortic valve is considered as a functional anatomical unit that includes many separate anatomical components but is unified in morphology and physiological role to ensure the aortic valve to function normally According to the author Carpentier, there are functional anatomical components: the annulus, the leaflets, the sinuses of Valsalva and the sinus-tubular junction - Structure features include: Valve ring; Leaf valve; Sinus-tube junction According to Carpentier, the structure of risk of damage in aortic valve replacement: bundle of His (located just below the right coronary valve margin - non-coronary); Mitral valve (located along the sinus of Valsalva left coronary – non-coronary); The common body of the left coronary artery is located behind the right-left coronary valve edge 3 - During surgery, keep in mind the constants of the aortic valve leaflet: Height (H)/Length (L) at the free border = 0.9; Height of pressure area (h)/Level height of valve (H) = ¼; Valve circumference (C) / blade length (L): C = 1/5L 1.1.2 Pathophysiological features of aortic valve stenosis The normal opening area of the aortic valve is 3-5 cm2 HC is very severe when the valve opening area is < 0.75 cm2 (or < 0.5 cm2/1m2 BSA) Syncope is a less common symptom in only about 35% of cases of aortic stenosis and usually follows exercise This may be due to arrhythmias or atrioventricular block Causes of HC are often due to rheumatic heart disease, degenerative and congenital 1.2 Symptoms and diagnosis of aortic valve stenosis When you have mild AS, you usually don't feel any symptoms Functions: dyspnea on exertion, angina pectoris, dizziness or fainting on exertion, paroxysmal dyspnea or fatigue According to the literature, when symptoms appear, only 35% of patients survival after years and after 10 years 10% Physical symptoms: palpating the carotid artery, palpating the apex of the heart, listening to the heart sound Subclinical: ECG: When having HC, there is usually left atrial thickening (80%), left ventricular hypertrophy (85%) and 10% normal Chest X-ray image: little diagnostic value for aortic stenosis - Echocardiography: (1) Evaluation of valve status, causes of valve stenosis; (2) Evaluation of hemodynamics Criteria for aortic stenosis: (according to Baumgartner H.-2017): mild (v: 2.6 - 2.9; Mean PG: < 20; AVA > 1.5; V1/V2 > 0.5; AVAI > , 85) Medium (v: – 4; Mean PG: 20 - 40; AVA: - 1.5; V1/V2: 0.25 0.5; AVAI: 0.6 - 0.85) Severe (v > 4; Mean PG: > 40; AVA < 1; V1/V2 < 0.25; AVAI < 0.6) - Cardiac catheterization and cardiac imaging: help to detect hemodynamics and damage to parts of the heart - Exercise testing: contraindicated in severe aortic stenosis with obvious functional symptoms (NYHA 3, 4) Stress ECG, stress myocardial radiography, and dobutamine echocardiography 4 - CT - chest scan with contrast: examine the aorta before surgery or consider indications for aortic valve surgery 1.2.3 Diagnosis of aortic valve stenosis The diagnosis of aortic stenosis should be considered in a patient with an ejection systolic murmur in the upper right sternal border, spreading to the carotid artery, and a history (coarctation of the aorta or rheumatic heart) and symptoms: pain chest, dizziness, fainting, and heart failure The main clinical examination is echocardiography 1.3 Treatment methods for aortic valve stenosis 1.3.1 Internally medical treatment According to the literature, clinically asymptomatic aortic stenosis does not currently have a specific medical treatment regimen, and patients with symptomatic HF require surgery rather than medical treatment 1.3.2 Intervention - Intra-aortic balloon placement: is a temporary method to stabilize the patient's condition - Percutaneous balloon aortic valve angioplasty: is an effective treatment for about years and the risk of death is low (2%) 1.3.3 Surgery It is an effective treatment method for patients with aortic stenosis today 1.3.4 New methods of replacing aortic valve - Transcatheter aortic valve replacement (TAVI): is a technique performed on patients with tight aortic valve stenosis when the risk of surgery is high - Ozaki valve replacement method: replacing the narrowed heart valve with the patient's own pericardium 1.4 Artificial aortic valve 1.4.1 Research history - In 1952, Hunfnagel was the first person to place an aortic prosthetic valve, the field of artificial heart valves has developed strongly Among the area indicators GOA, COA, EOA, EOA is the most interested because EOA is the area through which the blood flow through the valve, usually taking the EOA index per 1m² BSA (IEOA) The IEOA index with unsuitable aortic valve replacement was 0.85 cm²/m²); medium (0.65 - 0.85 cm²/m²); heavy ( 75% Inflammatory cell infiltration (inflammation is assessed by counting inflammatory cells on tissue fragments) Grade 0: no inflammatory cells; Grade 1: total inflammatory cells < 20 cells; Grade 2: total inflammatory cells from 20 to 50 cells; Grade 3: total inflammatory cells > 50 cells Vascular characteristics (% of cases with neovascularization): Proliferative: Small vessels with thick wall, clearly visible endothelial cells Nonproliferative: medium or large vessels, not visible endothelial cells were assessed by qualitative estimation: Grade 0: no thickening of the valve margin, no deformity; Grade 1: thickening of the valve only at the rim; Grade 2: thickening of the valve in the lower region valve edge; Grade 3: valve thickening, valve deformation Immunohistochemistry: Immunohistochemical staining slides were cut from the same specimen cast in paraffin candle blocks, previously cut and stained with HE, and stained with an automatic histochemical staining machine BenchMark Ultra, Ventana (Roche) The procedure is as follows: Cut - 4μm with cutter HM325 (Microm, Germany) on positively charged slide (Hydrophilic Slide/BioSB - USA) and dry at 370C overnight Boot, creating protocols for each autoantibody, CD3, CD20, CD34, CD68 selection DAB Detection Kit UtralView: Expression SMA (% of cases with positive fibroblasts): mark start 10 coloring in the cytoplasm; The number of T and B lymphocytes (% of inflammatory T-cell infiltration and % of B-lymphocyte infiltrate): cytoplasmic staining; Number of macrophages (% of macrophage cell infiltration): cytoplasmic stain Read the result: Negative (-): only the green color of the kernel Positive (+): yellow-brown color Post-operative study indicators: At ICU: (1) Hemodynamics (good: heart rate < 100 beats/min, systolic blood pressure > 90 mmHg, mean blood pressure > 60 mmHg, central venous pressure) < 14 mmHg); Respiration (frequency; oxygen saturation; INR); (2) Clinical: good, moderate, poor (3) Subclinical: electrocardiogram (complete right bundle branch block: QRS complexes in the form of rSR' or sR' or R with hooks in V1, and wide s in I, V6 and QRS magnitude longer than 0.12s ; Myocardial infarction: when a new Q wave appears or CKMB increases more than 10 times normal, or Troponin I is greater than ng/ml); Echocardiography, prosthetic valve function, paravalvular regurgitation (4) Complications (early death: < 30 days after surgery): stroke: acute onset of local or global neurological disturbance and lasting more than 24 hours; Convulsions: involuntary tremors in one or more muscle groups; Low-output syndrome (cardiac index < l/min/m² and systolic blood pressure < 90 mmHg associated with signs of tissue hypoperfusion: cold periphery, moist skin, oliguria (< 0.5) ml/kg/hour), hyperlactatemia in the absence of hypovolemia) With ventilatorassociated pneumonia, usually occurs after 48 hours and is based on the American Thoracic Society's diagnostic criteria - CPIS score ≥ CPIS score proposed by Pugin J et al in 1991: sputum secretion; upper infiltration; temperature; white blood cells (T/L); PaO2/FiO2 and culture of the aspirate Diagnosis is confirmed when there are criteria (1), (2) and at least of the criteria (3), (4), (5); sepsis: blood culture +) (5) Time of mechanical ventilation (hours): calculated from the time the ventilator is used until the time the ventilator is removed: < 12 hours; 12 – 24 hours; > 24 hours (6) Complications related to prosthetic aorta: thromboembolic valve obstruction (ACC/AHA: appearance of dyspnoea and/embolic symptoms, coagulopathy, and ultrasound hypomotility), loss proportionality between prosthetic valve size compared with the patient (IEOA 8.3 mmol/l; blood creatinine > 115 mmol/l) Internal therapy, peritoneal dialysis or hemodialysis; Postoperative liver failure (defined postoperatively with jaundice, rapidly increasing mucous membranes, dark urine and hepatic encephalopathy syndrome (classes I to IV) and elevated post-operative liver enzymes: GOT, GPT, Bilirubin, prolonged prothrombin time ≥ 1.5) Gastrointestinal bleeding after surgery: is determined if there are blood clots in the vomit, black, pasty, clammy stools and clinical anemia; In addition, complications of acute heart failure, acute cardiac tamponade (BECK triad and ultrasound results: right atrial collapse right ventricular collapse during diastole, pericardial effusion) were also monitored - Indicators to evaluate early results after surgery (in the first 30 days after surgery): Clinical: NYHA; Clinical criteria (good, moderate, bad) Subclinical: (re-examination week after discharge): Postoperative echocardiography includes: Dd, Ds, EF%; Pressure differential across the artificial aortic valve; AVA; The operation of the artificial aortic valve: good or not good (The vane opens and closes unevenly or even one or both vanes limit the operation; the valve side opening area > cm2 and the opening flow length > 1.5 cm ; aortic regurgitation ≤ 250 ms or reverse flow in descending aorta; differential pressure > 20 mmHg) - Research indicators for periodic follow-up after surgery (from the 3rd month after surgery): every months of the following months and every months of the following years Clinically: NYHA; Criterion good, moderate, not clinically good Subclinical: Electrocardiogram (Solokhop lyon, electrocardiographic axis, frequency, ST - T); Transthoracic echocardiography: Cardiac morphology (Dd, Ds, TT volume, TT volume index); Artificial aortic valve (AVA; Mean PG, valve actuation, valve edge opening, valve operation and valve 12 operating abnormalities); EF% Table Evaluation of Prosthetic Aortic Valves * Source: Nishimura R.A et al (2017) Complications at the time of postoperative follow-up: INR: – and adjusted according to the Guidelines for Warfarin Management in the Community Complications due to thrombosis: ischemic stroke; complications of peripheral vascular occlusion, prosthetic valve thrombosis (abnormal dyspnea, mechanical valvular sound is not clear, echocardiography shows limited valvular movement) Complications of prosthetic valve: mechanical failure; hemolysis; PPM Other complications: infective endocarditis; pannus 2.3 Analyzing data The data were entered and analyzed using SPSS 20.0 software Descriptive statistics: descriptive quantitative variables are the mean ± standard deviation Qualitative variables describe by, frequency, percentage The difference between two quantitative variables was determined by independent t-test if normally distributed or MannWhitney test if non-normally distributed Compare two ratios using the X² algorithm Compare two averages using the t-test algorithm Expressed as frequency or %, p values < 0.05 were considered to be statistically significant CHAPTER 3: RESEARCH RESULTS 3.1 General characteristics of the research group 13 - Patients < 70 years old accounted for 64.2% and ≥ 70 years old accounted for 35.8% The mean age of the study group was 65.0 ± 9.3 years old Predominantly male 68.7% (n = 46), male/female ratio = 2.2 Prognosis of early mortality after surgery with low risk (≤ 2%) is 50.5%, high risk (≥ 6%) accounts for 12.0% Rheumatic heart disease is the leading cause of AS in our country with 46.3% being treated according to the protocol In particular, 16.4% of patients had a history of rheumatic heart disease but did not receive treatment The combined diseases of the study group were quite diverse, in which hypertension accounted for 35.8% Some other chronic diseases have low rates such as diabetes (7.5%), coronary heart disease (11.9%) 3.2 Clinical and paraclinical characteristics - Clinical features: NYHA classification of heart failure with moderate and severe accounted for 100%, of which NYHA accounted for 58.2% There was no NYHA in this study Chest pain on exertion accounted for 59.7%, 3/6 systolic murmur in aortic valve locus appeared in 100% of patients, late carotid sign was 61.2%, and T2 was separated or reversed 56.7 % Enlarged liver accounts for 38.8% - Paraclinical characteristics: Preoperative sinus rhythm accounted for 94%, arrhythmias were uncommon and atrial fibrillation rate accounted for 6% The results of the electrocardiogram showed images suggesting thickening of the LV, accounting for 95.5% with the left axis image, only 4.5% of the medial axis on the ECG Image of enlarged heart on straight chest X-ray film with an average heart-thoracic index of 67.1 ± 3.9% Cardiac - thoracic index ≥ 50% accounted for mainly with 97% Echocardiographic results: AVA (cm²): 0.71 ± 0.1; LVEDd (mm): 49.5 ± 8.8; LVEDs (mm): 33.3 ± 7.6; LVEF (%): 60.9 ± 12.4; Mean PG (mmHg): 57.5 ± 12.0; Severe stenosis – tightness is 97.1%; The pressure difference across the aortic valve is mainly > 40 mmHg, accounting for 95.7%; LVMI: 194 ± 19.5 g (difference in LVMI by sex with p > 0.05) Coronary angiography results: CAD was found in 27.5% of cases, more lesions were found in the left branch, accounting for 18.8%, and the right branch in 8.7% Injury to the valve structure in 100% of the cases, in which the complete damage to the rheumatic group accounted for a high rate (31%), the nonrheumatic group mainly damaged part of the valve structure (78%) 14 Calcification of valve tissue: 25 - 75%; no neovascularization accounts for > 60%; mainly infected with Lymphocyte T (> 83%), Lympho B (> 48%) 3.3 Results of valve replacement surgery for aortic stenosis - Results of surgery: The time of clamping the aorta was 72.9 ± 38.0 minutes; Machine running time 112.9 ± 96 minutes; Causes of aortic stenosis: rheumatic heart disease (60%), degenerative (29.6%) congenital (10.4%) AS causes were found in both age groups Rheumatic heart disease is more common in the group < 70 years old and degenerative causes are more common in the group of patients ≥ 70 years old The most used mechanical valves are St.Jude valves and Sorin valves account for mainly 63.8% Valve size 21 is commonly used, accounting for 58%, valve size 23 is also used a lot with 23.2% of cases IEOA types of aortic valve replacement are suitable for the patient's body in 100% of the cases During the surgery, there was 01 patient with aortic root laceration which was detected early and promptly treated in surgery - Early results: no patients died prematurely Hemodynamically stable 95.5%, Average extubation time 17.7 ± 12.5 hours, extubation mainly in 12-24 hours After surgery, the degree of heart failure according to NYHA was mainly converted to NYHA I with 37.3%, severe heart failure was only 7.5%, when compared with preoperative results the difference was statistically significant with p = 0.016 ECG: atrial fibrillation slightly increased 7.4%; intermediate transfer axis; Sokolow – Lyon index was 31.1 ± 2.9 mm compared to preoperative (p < 0.05) Significant changes in echocardiography included: AVA (cm2): 1.90 ± 0.17; LVEDd (mm): 45.4 ± 6.4; LVEDs (mm): 30.8 ± 7.0; LVM (g): 141.8 ± 10.2; LVMI (g/m2): 130 ± 12 EF% difference was not significant (59.0 ± 13.0), Mean PG < 20 mmHg (91%), suggesting stenosis 9.0% The artificial valve works 100%, valve side opening 4.5% with opening area < cm², open flow length < 1.5 cm Complications accounted for a low rate such as ventricular fibrillation, pneumonia accounted for 1.5%, acute renal failure (not on dialysis) accounted for 3% - Mid-term follow-up results: NYHA increased from 0% to 86.4% after 12 months NHYA decreased from 41.8% to 16.4%, NYHA decreased from 58.2% to 7.5% after months of surgery Pairwise comparison in 12 months after surgery is significant p(3-0) = 0.001, p(6-3) = 0.008 and not significant p(12-6) = 0.56 After the first year of 15 pairwise comparison there was no difference p(24-12) = 0.65; p(36-24) = 0.16; p¬(48-36) = 1.00 The result of the span has no difference with p(3-0) = 1.00; p(6-3) = 0.98; p(12-6) = 0.73; p(24-12) = 0.92; p(36-24) = 0.88; p(48-36) = 0.92 Sokolow-Lyon index decreased slowly p > 0.05 Echocardiographic indices: AVA, Mean PG, LVEDd and LVEDs changed significantly in the first months after surgery (p < 0.005), from 12 months, p > 0.05 LVEF% was stable and this function was preserved, with low EF% group ( 1.5 cm² and no difference between the biological and mechanical valve groups Figure Mechanical AVA and medium-term differential pressure Comparing the pair of LVMI indexes, the LV regression after surgery was significant in the first years with p(3-0) = 0.001; p(6-3) = 0.001; p(12-6) = 0.001; p(24-12) = 0.001; p(36-24) = 0.002 Longer follow-up did not show LV regression p(48-36) = 0.233) LVMI was linearly correlated before and after 12 months after surgery according to the equation y = 92.4 + 0.216x, r = 0.44, p < 0.001 Factors affecting LVMI include hypertension (p = 0.001) and PPM (p = 0.005) Hypertension and PPM have a significant effect on LVMI according to model (LVMI = 130.1 + 7*THA + 7.4*PPM with R² = 0.244) the post-probability probability is the largest, helping to solve the problem The preferred LVMI variation is 24.4% With the BMA method showing female sex, age (≥ 70) has little impact on LVMI 16 LVMI tends to return to normal over time after surgery After 24 months it was estimated that 55.0% (95%CI: 43.5 - 69.4%) and after 48 months 37.9% (95%CI: 27.0 - 53.3%) had LVMI or higher The normal return of the hypertensive group was lower than that of the nonhypertensive group (p < 0.05) and equal to 3.62 (95% CI: 1.2 - 6.7) - PPM and related factors: During the follow-up period, there were 1.5 - 20% of patients with mild PPM at the time of follow-up, with IEOA in the range of 0.85 - 1.2 cm2/m2 The results show that factors such as female gender, diabetes have a risk of leading to PPM, the difference is statistically significant with p < 0.05 Other factors such as VSH, hypertension, valve size ≥ 21 did not increase the risk of PPM (p > 0.05) The mean pressure difference across the prosthetic aortic valve has a strong correlation with IEOA according to the quadratic equation with p < 0.001 Linear regression equation Y = 115 - 178x + 76.6x2 with R² = 0.631 NYHA higher in PPM group compared with no PPM The PPM group tended to gradually increase the NYHA rate The group of patients without PPM had higher LVMI return to normal than the PPM group, the difference was statistically significant with p < 0.05 and the risk ratio was 3.39 times (95% CI: 1.2 - 9,62) During follow-up, common bleeding complications can be at any time of follow-up with the rate from 2.5 to 3.8%, however, there are subcutaneous hemorrhages and bleeding gums Less common complications accounted stuck valve 5.5; MPI (Tei index) > 0.42; valve ring change (By TDI) < 12 mm; Left ventricular pressure < 10%; calcium index (on CT AV film) > 1650 AU and BNP > 550 pg/m In our study these tools were not applied The mean difference in pressure was 57.5 ± 12.0 mmHg and > 40 mmHg accounted for 95.5% This result is consistent with the pathophysiology of AS, causing pressure overload on the left heart leading to LV thickening, when AS is severe or tight, it will create a high pressure difference across the valve and this pressure difference will be highest in the AS group and is a factor It is important to help diagnose and decide on surgery High LVMI is associated with death and heart failure, author Dahl J.S found a strong correlation (HR: 1.53, 95% CI, 1.26 - 1.85, p < 0.001) Author Hachiro K LV muscle mass regression was independently associated with men and LVM The results of histopathology - immunohistochemistry showed that the AS group due to rheumatic heart disease had more damage to the valve structure, increased calcium, increased neovascularization and lower B, T lymphocytes when compared with the group due to degenerative and congenital This is a novel result of this thesis that helps to indicate the right surgery for the patient 4.3 Outcomes after valve replacement surgery for aortic stenosis - Surgery and complications: The average running time (minutes) is 112 ± 96 minutes, higher than the results of Duong Duc Hung et al., the running time is 95 ± 21.3 minutes and Swinkels B was 92.7 ± 42.5 and found that long machine running time was independently associated with decreased postoperative survival in severe AS group In the same opinion, author Chalmers J and colleagues studied 1863 patients with aortic valve replacement and found that running time is an important factor determining mediastinal ischemia, resuscitation, length of hospital stay and risk of death death The difference in time is mainly due to the characteristics of pathological lesions of the aortic valve and the associated injuries during aortic valve replacement When 19 comparing the time of aortic clamping and running time by age group, it was found that the age group < 70 years old, this time lasted longer than the group ≥ 70 years old, possibly due to the cause of AS in the group < 70 years old mainly due to low age Heart with many complex lesions in the aortic valve apparatus should prolong this time The most commonly used artificial valve for aortic valve replacement is the learned valve (76.1%) of which St Jude Regent (35.8%), Sorin Bicarbon (29.9%) Biological valves (23.9%) include: Biocor (11.9%), Hancock (7.5%), ATS (6%) In contrast to developed countries, Brennan J.M et al., the proportion of biological valves accounts for mainly 63% compared to mechanical valves of 27% and similar authors Duong Duc Hung et al., and Sharabiani M.TA and associates Valve size 21 is the most used with EOA:1.5 - 1.8 cm², with valve size 23 1.6 - 2.0 cm² is suitable for the majority of adult Vietnamese and finds it suitable This case is 100% There was patient having an intraoperative complication, accounting for 1.5% This patient after valve replacement, the heart beats well, but when the chest is closed, he discovers heavy bleeding at the origin of the aorta Proceed to reopen the chest, check for bleeding at the posterior aortic suture due to tearing of the artery wall Quickly recalibrate, rerun CEC, and arrest cardiac arrest The aorta was sutured with layers, reinforced with bioglue, closed the chest and then the patient was stabilized in the postoperative recovery room - Early results (in 30 days): 0% early mortality, Brennan J.M is 2.5%, author Hahn R.T predictors of early death: increase in LV volume, decrease in EF% and PPM Hemodynamic stability accounts for 95.5% with pulse, blood pressure within normal limits NYHA mainly converted to grade and 2, accounting for 92.5%, while 100% of NYHA and before surgery, showing a clear effect of aortic valve replacement surgery Author Durand E.D and Rathore S found this to be a factor in improving the patient's overall condition Arrhythmias such as atrial fibrillation, which usually appear 3-6 days after surgery, suggest that cardiac surgery may be a risk factor for early atrial fibrillation related to activation of the angiotensin system SokolowLyon was 31.1 ± 2.9 mm, significantly reduced after surgery and 20 different from before surgery (p < 0.05) According to ACC/AHA, there is a correlation between this index and LVMI with high sensitivity and specificity Echocardiography: AVA, EF%, Mean PG, LVEDd, LVEDs, LVMI, LVM and compared with preoperative results showed a decrease in AVA, Mean PG and LVMI indexes with p < 0.05 This result is consistent with studies in the country as well as in the world because when the LV afterload is reduced, the LV function is improved According to the author Lomivorotov V.V even patients with low EF% before surgery have good clinical and LV ejection fraction improvement LVEDd and LVEDs decreased compared with before surgery with p > 0.05, this is consistent with the literature on the pathophysiology of HC, this is an important parameter to evaluate the phenomenon of LV dilatation in HC disease and the structural deterioration LV architecture is still a big question According to Hahn R.T marked improvement in pressure gradient, postoperative AVA (p < 0.0001) and remained stable for years According to Gaudino M LVM decreased from 190 ± 43 g/m² to 158 ± 70 g/m² (p < 0.001), which is consistent with our results and the author found that LVM reduction was not correlated with clinical outcomes after surgery The artificial valve works well is 100% Early complications are common with low rates such as subcutaneous hemorrhage (3%), pneumonia (1.5%), ventricular fibrillation (1.5%) and acute renal failure (3%) lower than Cho Ray: the rate of bacteremia accounted for 4%, pneumonia 2% and complications of myocardial infarction was 4.1% Compare with Brennan J.M.: stroke (14.1%), hemorrhage (17.9%) Acute kidney failure usually resolves within a few days Helgason (2016) results showed that 45% of patients with acute renal failure had 4.1% of patients on dialysis and the author found that acute renal failure was a factor in increasing early mortality with p < 0.001 Ventricular fibrillation in 1.5% is usually due to electrolyte disturbances after surgery According to Pernigo M the severity of heart failure and the higher the age, the higher the arrhythmia complications Author Fischlein T et al recorded the rate of myocardial infarction is 2.5%, 21 similar to our study There are many factors that increase the risk of myocardial infarction after surgery, such as tri-vessel or common trunk disease, unstable angina, decreased LV function, prolonged aortic clamping time, and arterial endarterectomy coronary artery Infectious complications we encountered 1.5% pneumonia lower than author Mack M.J have a rate of lung infection is 19%, urinary tract infection is 4%, sepsis is 6% Factors associated with complications include age, duration of mechanical ventilation, feeding time with nasogastric tube, ability to take care of the incision - Results of medium-term follow-up: increase in NYHA and 2, decrease in NYHA and after surgery, mainly early and in the first months after surgery with p < 0.005 The favorable change of NYHA grade is one of the success factors of surgery Studies around the world have shown that ECG has little meaning in assessing AS and in this study we also found that However, with a decrease in LV outlet pressure, the heart wall tends to contract, so the Sokolow - Lyon index changes and happens slowly over time Echocardiographic results were within normal limits from month with LVEDd, LVEDs and Mean PG decreased and stable EF% improved significantly after valve replacement surgery (p < 0.05), EF < 50% group improved significantly and maintained with threshold > 50% Gaudino M after year of follow-up mean EF increased from 55 ± 21% to 57 ± 16% The prosthetic valve worked well with a suitable IEOA of about 1.5 cm²/BSA, Mean PG < 20 mmHg, and paravalvular regurgitation did not appear after months Mean PG in the 3rd month decreased significantly (p < 0.001), the following follow-up times tended to be stable < 20 mmHg (p > 0.05), study PARTNER (2015) also showed that, after surgery - years change does not make sense Results of LVMI index after months of surgery significantly decreased with p = 0.001 This result did not change at the next follow-up time In the PARTNER study, after aortic valve replacement, the average LVMI was 140 ± 36.0 g/m2, author Gaudino M was 190 ± 43 g/m2, after months it was 162 ± 69 g/m2, after 36 months it was 158 ± 70 g/m2 LV muscle 22 degeneration has a linear correlation with a weak correlation: r = 0.44 and p < 0.001, similar to the author Roscitano A R2 = 0.24, in addition, PPM does not affect mass regression LV muscle in patients > 65 years old, the author suggested that in the elderly, cardiac output demand is low even when the aortic orifice changes Hypertension and PPM status affect LVMI, through covariate analysis with preoperative LVMI according to the equation LVMI = 130.1 + 7.0*THA + 7.4*PPM (g/m2), helped explain 24.4% of the variation in LVMI after year of valve replacement surgery and hypertension had a slower rate of LVMI return to normal and less than the non-hypertensive group with a rate of 3.62 (95) %CI: 1.2 – 6.7) Valve size ≥ 21 did not affect LVMI after year of surgery, which suggests that choosing the right valve size for the patient will help improve myocardial hypertrophy Author Lund O (2003) monitoring the LVMI of AS patients after 10 years, the results showed that the majority of patients had LVMI improved after valve replacement, LVMI in the hypertensive group tended to increase again after 1, - 10 years The study by Gaudino M et al showed that hypertension is associated with LVMI in AS patients Author Muta E.M found that post-operative high LVMI was related to female gender, hypertension The significant risks (death, heart disease requiring hospitalization) at 5-year follow-up in groups of high and non-high LVMI were significantly different (95%CI: 1.26 - 1.85, p < 0.001) - PPM mainly appeared in the medium term and increased the adverse events after valve replacement with the rate of about 1.5 - 20%, lower than other studies abroad with the rate of severe PPM - 10%, mild PPM is 10 - 80% The result difference is due to the cause of HC, so the rate of using more VSH in these studies Mean PG has a strong correlation with IEOA index according to the equation Y = 115 - 178x + 76.6x2 (R² = 0.631, p < 0.001), similar to the research results of Pibarot P and Dumesnil J.G (r = 0.79) Besides the PPM results related to the clinical degree of heart failure, the author Ryomoto M found that 33.6% PPM did not affect the degree of heart failure PPM is associated with mortality, reports show that patients with severe PPM have a significantly worse 23 survival rate than those without this phenomenon, so if PPM with EF% < 40%, the mortality rate is high 77 times higher than in patients with normal EF The predictors according to the author Bilkhu R include: female, advanced age, hypertension, diabetes and renal failure The authors also recognize that PPM may be a marker of comorbidities rather than a risk factor for adverse outcomes and that PPM should be suspected in patients with persistent cardiovascular symptoms after surgery replace the aortic valve PPM increased NYHA grade and slowed LVMI progression (p < 0.05) The PPM group had the LVMI rate returning to normal by 3.39 (95%CI: 0.12 – 9.62) Thus, although the PPM is mild, it has somewhat affected the reversal of heart failure after valve replacement CONCLUSION Through the study of 67 patients with valve replacement for aortic stenosis at Military central Hospital 108, some conclusions are as follows: Clinical and subclinical characteristics Patients with aortic stenosis come to the hospital at a late stage when functional and physical symptoms appear with a high rate such as dyspnea and systolic murmur 3/6 of the aortic valve region is 100%, NYHA and account for 100% Echocardiography showed dilated left heart with LVEDd: 49.5 ± 8.8 mm, LVEDs: 33.3 ± 7.6 mm and preserved EF%: 60.9 ± 12.4% Severe stenosis and tight with AVA: 0.71 ± 0.1 cm2 and Mean PG: 57.5 ± 12 mmHg Increase in left ventricular muscle mass: 194 ± 19.5 g/m² Pathological results were atypical in the low and non-low group, but the rate was higher in the low group with features of vandal structure destruction, calcium infiltration and neovascularization Increased B, T lymphocytes in the group is not due to low Results of aortic valve replacement surgery Mechanical valves are used mainly, valve size 21 accounts for 59.7% and IEOA > 0.85 cm²/m²) Complications in surgery are low (1.5%) Early postoperative results improved significantly (p < 0.05) when compared with preoperative: NYHA changed to and 2, Mean PG < 20 mmHg and remained stable EF% was preserved and tended to increase slightly in the 24 group < 50% before surgery 100% of patients after surgery have a wellfunctioning prosthetic valve and low surgical complications 3% The medium-term results showed that NHYA accounted for the majority (85.1%), the echocardiographic index was within normal limits The prosthetic aortic valve works well with differential pressure < 20 mmHg LVM regressed slowly after surgery with the Sokolow Lyon index significantly reduced compared to before surgery and remained stable < 35 mm LVMI 12 months postoperative was linearly correlated with LVMI at 12 months (r = 0.44, p < 0.01) and hypertension, PPM significantly influenced this regression (p = 0.001 and p) = 0.005) Postoperative PPM is mainly from the 2nd year after surgery with the rate of 1.5 - 20%, tends to increase with the follow-up time with risk factors: female (p = 0.005), diabetes (p = 0.005), diabetes (p = 0.005) p = 0.009) PPM affects the degree of gradient and heart failure after surgery Postoperative complications are low (≤ 3.8%) and complications of coagulopathy can be encountered at any time RECOMMENDATIONS It is necessary to monitor long-term outcomes after aortic valve replacement surgery and changes in left ventricular muscle mass, factors affecting PPM and PPM consequences to make recommendations tailored to each patient ... AVA; The operation of the artificial aortic valve: good or not good (The vane opens and closes unevenly or even one or both vanes limit the operation; the valve side opening area > cm2 and the opening... electrocardiographic axis, frequency, ST - T); Transthoracic echocardiography: Cardiac morphology (Dd, Ds, TT volume, TT volume index); Artificial aortic valve (AVA; Mean PG, valve actuation, valve edge opening,... acid solution for 24 hours Specimens were mixed into numbered pieces and then put into the cassette, processed by Tissue - Tek VIP6AI automatic tissue processing machine of Sakura, Japan Indicators
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