Abstract 1621: Long-Term Prognosis in Patients with Obstructive Hypertrophic Cardiomyopathy: A Comparison between Left Ventricular Outflow Tract and Mid Cavity Obstruction
Management strategies and prognosis in outflow-tract obstructive hypertrophic cardiomyopathy (OTO-HCM) have been evaluated. However, clinical profiles or prognosis in patients (pts) with mid-cavity obstructive HCM (MO-HCM) is unclear. The purpose of this study was to describe and compare long-term prognosis between pts with OTO and MO-HCM.
Methods: A retrospective study of 430 pts with HCM, who were diagnosed and followed-up in our hospital, was analyzed. OTO and MO-HCM were defined as having left ventricular pressure-gradient (PG) > 30mmHg, measured by under basal condition at echocardiography. Among 430 HCM pts, 96 pts (22%) were diagnosed as OTO-HCM and 45 pts (11%) as MO-HCM. We analyzed HCM-related morbidity (stroke, syncope, or heart failure) and HCM-related mortality (stroke related death, heart failure related death, or sudden death) in pts with OTO and MO-HCM during a mean follow-up of 7.2±5.5 years.
Results: The PG in MO-HCM was significantly lower than those in OTO-HCM (46±16 and 77±27 mmHg, p<0.001). The frequency of HCM-related morbidity in MO-HCM was similar to those with OTO-HCM (26.7% and 27.1%, respectively). Regarding HCM-related death, there was no significant difference between pts with MO and OTO-HCM (p=0.668, Figure⇓). Furthermore, the probability of sudden death in MO-HCM was similar to those with OTO-HCM (p=0.739, Figure⇓).
Conclusions: This study demonstrates that the incidence of sudden death in MO-HCM was similar to those with OTO-HCM although the PG in MO-HCM was significantly lower than those in OTO-HCM. Therefore, in pts with MO-HCM, an aggressive prevention for cardiovascular death including sudden death should be considered as well as OTO-HCM.