Avaliação dos polimorfismos genéticos da enzima conversora de angiotensina e aldosterona nos indivíduos com cardiomiopatia hipertrófica

Abstract

Genetic polymorphisms of angiotensin converting enzyme and aldosterone synthase may influence phenotypic expression in individuals with hypertrophic cardiomyopathy (HCM). The aim of this study it is to determine the distribution of genetic polymorphism variants of angiotensin converting enzyme (ACE) and aldosterone synthase (CYP11B2) in individuals with hypertrophic cardiomyopathy and correlate with clinical, eletrocardiography and echocardiographic data. The patients (n=61) were evaluated through an interview, physical examination, laboratory tests, electrocardiogram, transthoracic echocardiogram and identification of variants of ACE e CYP11B2 genetic polymorphism.The population sample was homogeneously composed of males and females, mean age of 48.41±14.59 years, white individuals (52.5%). A family member with HCM were reported in 39.3%. The most prevalent comorbidity was systemic arterial hypertension (47.5%). The majority (86.9%) of the individuals were symptomatic and makes use of medication (93.4%). Only 6.6% have atrial fibrillation (AF), 14.8% presented left budle branch block (LBBB), and the mean QTc interval was 442.20±31.28 ms. The most prevalent echocardiographic type were types II and III. The mean left ventricular (LV) wall thickness was 18±3.48 mm, the mean left atrium (LA) diameter was 44.31±6.43 mm and the indexed left ventricular (LV) mass was 147.63±45.14 g/m2. The frequency of the ACE polymorphism genotypes was DD (24.59%), ID (60.65%), II (14.75%) and aldosterone synthase polymorphism TT (39.34%), TC (54.09%), CC (6.55%). There was a prevalence of DD (60%) and TT (58.3%) genotypes in male and genotypes II (55.6%) and CC (75%) in female. A family member with HCM were reported more often in individuals with the DI genotypes (45.9%) and TT (45.8%). A prevalence of the dyspnea symptom was observed in individuals with DD and DI (66.7% and 75.7%) and with CC and TC (100% and 69.7%). Systemic arterial hypertension is more frequently present in DD (53.3%) and CC (75%). ). AF were more often in TC (9.1%) and II (22.2%), LBBB in DD (26.7%) and TT (25%) and the bigger QTc interval in DD (447,87±27,57 ms). There was statistical significance when correlating the CC genothype and antiarrhythmic use (p = 0.039). There was a tendency of individuals with DD and II to present grade II diastolic dysfunction (53.3% and 55.6%, respectively) and, also, CC genotype, however, without statistical significance. There was a correlation between the obstructive form of HCM and the CC genotype (p = 0.035). In conclusion, the most common ACE polymorphism in our sample population is DI and aldosterone synthase polymorphism is CT. Individuals with the CC genotype of the aldosterone synthase polymorphism showed a more obstructive gradient and are who most antiarrhythmic drugs uses. (p=0.035 e p=0.039, respectively).