Features of Diagnostics and Course of Hypertrophic Cardiomyopathy in Real Clinical Practice

Abstract

Introduction and purpose. Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular (LV) wall thickening not associated with increased afterload (hypertension and aortic stenosis), is usually caused by mutations in sarcomeric protein genes, and is inherited in an autosomal dominant manner. Unlike HCM, myocardial hypertrophy in its phenocopies is associated with the accumulation of substances such as amyloid, glycogen, etc. in the myocardium. The aim of our work was to analyze the features of the diagnosis and course of HCM in real clinical practice. Material and methods. A retrospective analysis of medical records of 80 patients (56.3 % of men) discharged with a diagnosis of HCM from a multidisciplinary hospital in Moscow in the period from 2007 to 2021 was carried out. The diagnosis of HCM in all patients was established on the basis of echocardiography data. The median age (25th and 75th percentiles are indicated in brackets) was 57 (48.5; 63) years. The duration of hospitalization was 8 (6; 12.5) days. Results. The reason for hospitalization was angina syndrome in 35 %, suspicion of acute coronary syndrome in 16.3 %, paroxysmal atrial fibrillation (AF) in 11.3 %, decompensation of chronic heart failure in 11.3 %, syncope in 7.5 % %, hypertensive crisis in 3.8 %, coronary angiography in 3.8 %, pacemaker implantation in 2.5 %, consultation with an arrhythmologist in 2.5 %, implantation of a cardioverter-defibrillator in 1.2 %, medical examination to resolve the issue of fitness for military service in 1.2 %, acute cerebrovascular accident in 1.2 %, hypotension in 1.2 %, drug bradycardia in 1.2 % of patients. Before hospitalization, a history of myocardial infarction was diagnosed in 15 %, arterial hypertension — in 53.8 %, chronic heart failure — in 77.6 %, chronic kidney disease — in 21.3 % of patients. Prior to the analyzed hospitalization, a history of myocardial infarction was diagnosed in 15 %, arterial hypertension in 53.8 %, chronic heart failure in 77.6 %, chronic kidney disease in 21.3 % of patients. LV wall thickness ≥1.5 cm was detected in 91.2 %, symmetrical form of hypertrophy — 22.1 %, apical — 5.2 %, papillary muscle hypertrophy — 1.3 %, interventricular septum — 71.4 % of patients. Permanent obstruction of the LV outflow tract (LVOTO) was detected in 62.8 % (9.0 % of patients had a history of septal reduction), transient LVOTO — in 1.3 %, non-obstructive HCM — in 35.9 %. The ejection fraction (EF) of the LV (according to Simpson) was 63 (55-70) %, CHF with reduced LV EF <40 % was detected in 3.8 %, with a moderately reduced LV EF (40-49 %) — in 5 %, with preserved LV EF — in 68.8 % of patients. Anterior systolic movement of the anterior leaflet of the mitral valve occurred in 47.5 %, prolapse of the anterior leaflet of the mitral valve was described in 7.14 %. Mitral regurgitation was registered in 75 % of patients. 45 % of patients with HCM suffered from AF: permanent 15 %, paroxysmal 23.8 %, persistent 6.2 % of patients. During hospitalization, ventricular tachycardia was registered in 7.5 %, supraventricular tachycardia — 3.8 %, conduction disturbances were noted in 36.3 % of patients, of which atrioventricular block in 6.3 %, blockade of the right bundle branch block in 21.3 %, left bundle branch block in 15 %, and Wolff-Parkinson-White syndrome in 1.3 % . Implantation of a pacemaker in history was in 5 %, including in connection with MorgagniAdams-Stokes attacks — in 3.8 % of patients. During a median follow-up of 87 (interquartile range 45–131.5) months, 13.8 % of patients with HCM died. In deceased patients, LVOTO was significantly more common (in the dead 100 %, in the living 58.2 %, p = 0.006) and AF (in the dead 72.7 %, in the living 40.6 %, p = 0.047). Genetic testing and exclusion of HCM phenocopies was not performed during hospitalization and was not recommended for any patient. Conclusion. In real clinical practice, in most cases, only phenotypic diagnosis of HCM is carried out according to echocardiography, and screening for genetic mutations and HCM phenocopies is not performed. It is necessary to widely introduce genetic testing and screening for HCM phenocopies for the timely diagnosis of pathology that requires the appointment of specific pathogenetic therapy to improve the prognosis of patients