Prognostic impact of mitral L-wave in patients with hypertrophic cardiomyopathy without risk factors for sudden cardiac death.

Hypertrophic cardiomyopathy (HCM) with severe diastolic dysfunction is a major cause of heart failure and sudden cardiac death (SCD) associated with lethal arrhythmia. Although various risk factors for cardiac events have been reported in HCM patients, previous studies have reported that some HCM patients exhibit either no risk or a low risk of SCD experienced cardiac events. The mid-diastolic transmitral flow velocity curve (mitral L-wave) is an echocardiographic index of left ventricular compliance, and it has been reported as one of the parameters of advanced diastolic dysfunction assessed noninvasively. However, little is known about the association between the mitral L-wave and long-term clinical outcomes in HCM patients without SCD risk factors. Between July 2005 and February 2016, 112 patients were diagnosed with HCM and 96 patients without risk factors were enrolled. After excluding 3 patients whom we could not detect L-wave more than once, 93 patients (mean age 57.7 ± 13.1 years, 33 females) were divided into the following two groups, according to the presence or absence of the mitral L-wave: Group L (+) (with the mitral L-wave) and Group L (-) (without the mitral L-wave). The correlations between the mitral L-wave and rates of cardiac events were investigated. The mitral L-wave was present in 14 (15.1%) patients [Group L]. During the follow-up period [4.7 (2.9-7.5) years], patients experienced 7 cardiac events. Kaplan-Meier survival analysis showed that the event-free rate was significantly lower in Group L (+) than in Group L (-) (log-rank P = 0.002). Additionally, in multivariate analysis, L-wave positivity was identified as independent predictors of cardiac events. Existence of the mitral L-wave can predict cardiac events, even in HCM patients without SCD risk factors.

The Selvester QRS score as a predictor of cardiac events in nonischemic dilated cardiomyopathy.

BACKGROUND: Myocardial fibrosis is associated with poor prognosis in nonischemic dilated cardiomyopathy (NIDCM) patients. The Selvester QRS score on 12-lead electrocardiogram is associated with both the amount of myocardial scar and poor prognosis in myocardial infarction patients. However, its use in NIDCM patients is limited. We investigated the prognostic value of the QRS score and its association with collagen volume fraction (CVF) in NIDCM patients. METHODS: We enrolled 91 consecutive NIDCM patients (66 men, 53±13 years) without permanent pacemakers or cardiac resynchronization therapy devices. The Selvester QRS score was calculated by two expert cardiologists at NIDCM diagnosis. All patients were followed up over 4.5±3.2 years. Cardiac events were defined as a composite of cardiac death, hospitalization for worsening heart failure, and lethal arrhythmia. We also evaluated CVF using endomyocardial biopsy samples. RESULTS: At baseline, the left ventricular ejection fraction was 32±9%, plasma brain natriuretic peptide level was 80 [43-237] pg/mL, and mean Selvester QRS score was 4.1 points. Twenty cardiac events were observed (cardiac death, n=1; hospitalization for worsening heart failure, n=16; lethal arrhythmia, n=3). Cox proportional hazard regression analysis revealed that the Selvester QRS score was an independent determinant of cardiac events (hazard ratio, 1.32; 95% confidence interval, 1.05-1.67; p=0.02). The best cut-off value was determined as 3 points, with 85% sensitivity and 47% specificity (area under the curve, 0.688, p=0.011). In Kaplan-Meier survival analysis, the QRS score ≥3 group had more cardiac events than the QRS score <3 group (log-rank, p=0.007). Further, there was a significant positive correlation of Selvester QRS score with CVF (r=0.46, p<0.001). CONCLUSIONS: The Selvester QRS score can predict future cardiac events in NIDCM, reflecting myocardial fibrosis assessed by CVF.