Clinical variants, outcomes and prognosis of hypertrophic non-obstructive cardiomyopathy: results of long-term follow-up

Aim. Based on the results of a long-term follow-up, to determine the clinical variants of hypertrophic non-obstructive cardiomyopathy (HNOCM) and develop criteria for the progression of the disease.Material and methods. The results of long-term follow-up were evaluated for 97 patients with HNOCM, men — 57 (58,8%), women — 40 (41,2%), average age — 42,5±1,52 years (M±σ). The average follow-up was 11,0±5,73 years. Research methods were physical examination, electrocardiography (ECG), 24-hour ECG monitoring with assessment of heart rate variability, Doppler echocardiography (echo). Physical and instrumental re-examination of patients was used for determining of changes.Results. Clinical progression was detected in 46 (47,4%) patients. The most common progression variants were deterioration of chronic heart failure (54,3%), cardiac arrhythmias (45,7%) and a combined one (37%). The aggravation of echo data was found in 43 (44,3%) patients. The most frequent progression variants werecombination of different dynamics scenarios (79,1%), including a decrease in the mobility of left ventricle walls (67,4%), an increase of left atrium dimension (58,1%), and diastolic dysfunction deterioration (67,4%). Aggravation of myocardial hypertrophy was noted in only 3 cases. In 5 (5,15%) cases, the dilation stage of HNOCM was recorded. A scoring model for assessing of progression risk were proposed. It includes the duration of HNOCM >20 years, baseline ≥II FC chronic heart failure, ≥2 clinical manifestations of the disease, left ventricular myocardialmass index >200 g/m2 , left atrial volume index >34,0 ml/m2 , cardiac output <5 l/min, decrease in heart rate variability.Conclusion. HNOCM is a disease with a complicated prognosis, progressing in 64% of patients, more often with a long course. The clinical progression of HNOCM was manifested by the diverse dynamics of complaints. Structural and functional progression was manifested mainly by a combination of different dynamics variants (in 79,1% of cases), including a decrease in the mobility of left ventricular walls, an increase of left atrium dimension, aggravation of diastolic dysfunction, but not deterioration of myocardial hypertrophy. The main criteria for progression: disease duration >20 years, baseline ≥II FC chronic heart failure, ≥2 clinical manifestations of the disease, increase of left ventricular myocardial mass index and left atrial volume index, decrease of cardiac output and heart rate variability