P5553Right ventricular involvement in hypertrophic cardiomyopathy: insights from a tertiary centre

Abstract

Abstract Introduction Hypertrophic cardiomyopathy (HCM) is the main cause of sudden cardiac death in the young and a cause of heart failure (HF) and death at any age. Nevertheless, adverse long-term outcomes are not easy to predict. Objectives To assess the prevalence and prognostic value of right ventricular (RV) involvement in patients (pts) with HCM. Methods Retrospective single-centre study of consecutive pts with HCM evaluated in a specialized consultation. Selected those submitted to cardiac magnetic resonance imaging (CMR) as the gold-standard for RV assessment. The primary endpoint (PE) was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, ventricular arrhythmias with hemodynamic instability and unplanned HF admission. Results Of a total of 181 pts, 104 fulfilled the inclusion criteria (mean age at first consultation 62.1±9.7 years, 63.5% male). Septal asymmetric phenotype was the most frequent (73.1%) and 24 pts (23.1%) had rest LV outflow tract obstruction. Mean value of maximum wall thickness was 18.8±4.6 mm. Regarding CMR parameters (Fig A), 5.8% had RV dysfunction and 2.9% RV free wall hypertrophy; no patient presented RV dilation. Late gadolinium enhancement (LGE) of joint points was observed in 47.1%. During follow-up (FU, mean 56.6±29.5 months), survival free of RV dysfunction was 94.3%. Only 5 pts developed RV compromise assessed by echocardiographic parameters: TAPSE 12.0±3.4 mm and pulsed tissue Doppler systolic annular velocity (tricuspid S') wave 7.3±0.9 cm/s. These pts were significantly older (p<0.01) and had higher values of average tissue doppler E/E' ratio at diagnosis (p<0.01). Global RV involvement (at diagnosis or during FU) were associated with increased values of indexed left atrial area (p<0.01), LV dysfunction (p=0.01), LGE of joint points (p=0.01) and higher values of NT-proBNP (p=0.01). In multivariate logistic regression, left atrial enlargement was the only independent predictor of global RV dysfunction (OR 1.9, 95% CI 1.1–3.2, p=0.01) and average E/E' ratio an independent predictor of RV dysfunction during FU (OR 1.3, 95% CI 1.1–1.5, p<0.01). PE rate was 10.6%. It was significantly higher in pts with global RV involvement and there was a significant difference in survival analysis (Fig B). Average E/E' ratio (OR 1.5, 95% CI 1.1–1.9, p=0.01) and RV ejection fraction (OR 0.8, 95% CI 0.7–0.9, p=0.01) were independent predictors of the outcome. Conclusions Although not common, RV dysfunction was associated with a higher rate of cardiovascular events. Average E/E' ratio, as a measure of left ventricular filling pressure, was a risk factor for both RV dysfunction and PE. Higher values of RV ejection fraction were protective of adverse events occurrence. Together, these results support a potential role of RV function in the risk stratification of HCM pts.