Incidence, Clinical Characteristics, and Long-term Outcome of the Dilated Phase of Hypertrophic Cardiomyopathy

Abstract

Some patients with hypertrophic cardiomyopathy (HCM) develop systolic dysfunction, called the dilated phase of HCM (d-HCM), which is associated with increased morbidity and mortality. We conducted a retrospective study using an HCM database to clarify the incidence, clinical characteristics, and longterm outcomes of d-HCM. We analyzed an HCM cohort consisting of 434 patients (273 with apical HCM and 161 with non-apical HCM; 18 had obstructive HCM, 16 had dilated HCM, and 127 had other HCM) diagnosed by echocardiography in our hospital between 1991 and 2010. The follow-up period was 8.4 ± 6.7 years. The mean age at final follow-up was 67 ± 14 years, and 304 patients (70%) were men. The mean age of the 16 d-HCM patients at the initial visit was 45 ± 17 years, the age at final follow-up was 59 ± 18 years, and 13 were men. Thirteen d-HCM patients developed atrial fibrillation and six patients developed ischemic stroke. Twelve d-HCM patients were implanted with cardiac devices: one pacemaker, nine implantable cardioverter-defibrillators, and two cardiac resynchronization therapy with defibrillator. Five patients died of progressive heart failure at the age of 61 ± 23 years. The age at the initial visit and final follow-up were lower and the NYHA class, brain natriuretic peptide levels, and left ventricular function at initial evaluation were worse in the d-HCM group. Univariate analysis demonstrated that a lower age at the initial visit was associated with d-HCM (hazard ratio 0.955/1 year increase; 95% CI 0.920-0.991, P = 0.015). In our HCM cohort, the incidence of d-HCM was 4%. A high prevalence of atrial fibrillation and cerebral infarction and poor prognosis were noted in this group, despite patients undergoing medication and device implantation.

Very long‐term prognosis in patients with hypertrophic cardiomyopathy: a longitudinal study with a period of 20 years

“…Although the time course of LV remodelling is heterogeneous, LV remodelling often occurs gradually over the years 15,16 . Previous studies have shown that AF and end‐stage HCM are associated with worse clinical outcomes, 13,17–20 and 74% of the patients with AF and 86% of the patients with end‐stage HCM in the present study suffered from HCM‐related adverse events. Based on these facts, it is expected that the longer the follow‐up period is, the higher will be the frequency of development of AF and end‐stage HCM.…”

Predictive Factors for Decreasing Left Ventricular Ejection Fraction and Progression to the Dilated Phase of Hypertrophic Cardiomyopathy

“…LV performance at baseline is one of the predictors of DHCM development [6]. LVDs were the most sensitive echocardiographic parameter, reflecting LV contraction and LV cavity enlargement.…”

“…PTSMA is a septal reduction therapy for severe HOCM; however, many patients who are not candidates for surgical myectomy now receive this catheter-based procedure [8,9,22]. The long-term impact of PTSMA on LV contraction, particularly LV development, has not been thoroughly investigated because most previous studies excluded patients receiving septal reduction therapy from DHCM risk analyses [4][5][6]. The present study did not exclude patients with PTSMA because they represented one-fourth of the total patient population.…”

“…Notably, DHCM is associated with poor prognosis, with approximately 8.4 years (median) to death, requiring an LV assist device or transplantation [3]. Several studies have focused on identifying factors contributing to DHCM development; however, no definitive factors have been identified [4][5][6]. LVEF declines differently in patients with HCM, and no reliable algorithms exist to predict reduced LVEF [5,7].…”

“…Most previous studies investigating the factors influencing DHCM did not include patients undergoing septal reduction therapy, such as percutaneous transluminal septal myocardial ablation (PTSMA) [4][5][6]. The nonpharmacological intervention has a direct negative impact on LV contraction.…”