Association between traditional cardiovascular risk factors and clinical phenotype of hypertrophic cardiomyopathy

Despite the fact that the principles of diagnosing hypertrophic cardiomyopathy (HCM) are clearly defined in current guidelines, in real clinical practice one has to deal with a large number of comorbid patients where the diagnosis of HCM is not so obvious. Objective . To analyze the clinical and demographic characteristics of patients referred to the Almazov National Medical Research Center with the diagnosis of HCM. Design and methods . The registry included 1168 patients who were provisionally or definitively diagnosed with HCM in the period from 2010–2021. Out of them, 280 patients were excluded from the study. The patients included in the registry were divided into two groups: 1) patients meeting the criteria for HCM — 578 people (57,0 %); 2) patients of the so-called “gray zone” with the left ventricular wall thickness of 15-19 mm and concomitant arterial hypertension (HTN) — 310 (30,0 %) people. Results . In the first group of patients with HCM criteria, 326 (56,4 %) patients were aged 31–59 years and 35,5 % in the group older than 60 years. In the 2nd group there were 52,9 % (n = 164) patients older than 60 years, p < 0,001. 69,2 % of patients in the first group and 96,1 % of the 2nd group had a previous history of HTN. In relatives of patients of the first group, sudden cardiac death was more common — 3,5 versus 0,6 % in group 2, p < 0,05. Family history of HCM was observed in 6,2 % in group 1 versus 0,3 % in group 2, p < 0,001. In the first group, the obstructive form of HCM was more common — 54,5 versus 37,7 % in the second group, p < 0,001. Using logistic regression, the correctness of the classification of patients with HCM was assessed. The percentage of correct diagnoses was 94,1 % (Wald test = 78,317, p < 0,0001). Conclusions . Traditional risk factors, such as HTN and diabetes mellitus, not only make it difficult to diagnose HCM, but also aggravate its clinical presentation: myocardial hypertrophy, ventricular arrhythmias, and atrial fibrillation. The most important indicators in the classification of patients with suspected HCM were the thickness of the left ventricular wall according to echocardiographic data and the presence of HTN disproportionate to the degree of structural changes in the myocardium.