B-type natriuretic peptide and risk of sudden death in patients with hypertrophic cardiomyopathy.

BACKGROUND: The association between B-type natriuretic peptide (BNP) levels and sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM) remains unclear. OBJECTIVE: This study evaluated the effect of elevated BNP levels on sudden death risk in a cohort of patients with HCM. METHODS: This study included 346 patients with HCM. Plasma BNP levels were measured at the initial evaluation. RESULTS: The median (interquartile range) BNP level in the study patients was 197.2 (84.4-353.3) pg/mL. During a median (interquartile range) follow-up period of 8.4 (4.2-12.5) years, 37 patients (10.7%) experienced the combined end point of sudden death or potentially lethal arrhythmic events, including 11 patients with sudden death (3.2%), 8 resuscitated after cardiac arrest, and 18 with appropriate implantable defibrillator shocks. Time-dependent receiver operating characteristic curve analysis of the prognostic value of BNP for the combined end point showed that the Harrell's concordance index was 0.748 and the optimal BNP cutoff point was 312 pg/mL. Patients with high BNP levels (>312 pg/mL) were at a significantly higher risk of sudden death (Gray test, P = .001) and the combined end point (Gray test, P < .001) than were patients with low BNP levels (≤312 pg/mL). Multivariable analysis that included BNP levels and established risk factors for sudden death showed that high BNP levels were an independent determinant of the combined end point (adjusted hazard ratio 5.71; 95% confidence interval 2.86-11.4; P < .001). CONCLUSION: Elevated BNP levels may be associated with sudden death and the combination of sudden death or potentially lethal arrhythmic events in patients with HCM.

Association of elevated pulmonary artery systolic pressure with stroke and systemic embolic events in patients with hypertrophic cardiomyopathy.

BACKGROUND: Echocardiographically estimated pulmonary artery systolic pressure (PASP) is a non-invasive widely available method that is used to estimate pulmonary arterial pressure. Although elevated PASP predicts mortality in patients with hypertrophic cardiomyopathy (HCM), the relationship between PASP and embolic events is unclear. This study aimed to determine whether elevated PASP is associated with stroke and systemic embolic events in a tertiary referral HCM cohort. METHODS: This study included 374 clinically diagnosed patients with HCM. PASP was estimated from tricuspid regurgitant jet velocity using the modified Bernoulli equation. RESULTS: The median (interquartile range) PASP was 33 (28-37) mm Hg, and elevated PASP (>40mmHg) was observed in 66 (17.6%) patients. Seventeen of the 66 (25.8%) patients with elevated PASP and 24 of the 308 (7.8%) patients without elevated PASP experienced stroke and systemic embolic events during the 10.3±7.4years of follow-up (log-rank P<0.001). Multivariable analysis showed that age at diagnosis, atrial fibrillation, and PASP >40mmHg (adjusted hazard ratio, 2.59; 95% confidence interval, 1.31-5.12; P=0.006) were independently associated with embolic events. CONCLUSIONS: In addition to age and atrial fibrillation, PASP estimated by Doppler echocardiography could help embolic risk stratification in patients with HCM.

Prognostic impact of disseminated intravascular coagulation score in acute heart failure patients referred to a cardiac intensive care unit: a retrospective cohort study.

Thrombosis within the vascular system in relation to inflammation and stasis is potentially associated with poor prognosis in patients with heart failure. The aim of this study was to clarify the association between disseminated intravascular coagulation (DIC) score, a scoring system for microvascular thrombosis and multiple organ dysfunction, and outcome in hospitalized patients with acute heart failure (AHF). We retrospectively evaluated 160 AHF patients referred to a cardiac intensive care unit who had their DIC score measured according to the Japanese Association for Acute Medicine (JAAM) DIC scoring system on admission. Platelet count, prothrombin time ratio, fibrin/fibrinogen degradation products, and the criteria for systemic inflammatory response syndrome were measured. Using the JAAM DIC score, the prevalence of DIC (score ≥4) in AHF patients was 5.0% (8 of 160 patients). The risk of death for patients grouped according to the DIC score was 27.8%, 46.2%, and 87.5% for DIC scores 0-1, 2-3, and ≥4, respectively (median follow-up 460 days). In multivariate analysis adjusted for various markers of disease severity, a DIC score ≥2 was independently associated with a higher all-cause death rate (adjusted hazard ratio 2.45; P = 0.005) and a higher rate of reaching the combined endpoint of all-cause death and readmission for AHF (adjusted hazard ratio 2.10; P = 0.006) after admission for AHF. In an intensive care setting, measurement of DIC score on admission could help risk stratification in hospitalized patients with AHF.

Implantable cardioverter defibrillator therapy and sudden death risk stratification in hypertrophic cardiomyopathy patients with midventricular obstruction: A single-center experience.

BACKGROUND: Previous studies reported that the presence of midventricular obstruction (MVO) was an independent determinant of sudden death and potentially lethal arrhythmic events in patients with hypertrophic cardiomyopathy (HCM). However, it remains unclear whether implantable cardioverter defibrillator (ICD) improves survival in HCM patients with MVO. In addition, the risk factors for lethal arrhythmic events in MVO-HCM patients are not fully understood. The aim of this study was to provide an overview of the ICD therapy on sudden death prevention, and to determine the risk factors for lethal arrhythmic events in MVO-HCM patients. METHODS: This study included 593 HCM patients. Left ventricular MVO was diagnosed when the peak midventricular gradient was estimated as ≥30mmHg. RESULTS: MVO was identified in 56 patients (9.4%), and 15 of the 56 MVO-HCM patients (26.8%) received an ICD. Six of 15 ICD-implanted patients (40.0%) had appropriate ICD interventions over the follow-up period of 6.5±5.1years after ICD implantation. Although two of 42 patients without an ICD died suddenly, no patients experienced sudden death after ICD implantation in patients with an ICD throughout the follow-up period of 9.0±8.0years after referral to our hospital. By multivariate analysis, maximal wall thickness was an independent determinant of lethal arrhythmic events in MVO-HCM patients. CONCLUSIONS: A quarter of MVO-HCM patients received an ICD, and the incidence of appropriate ICD intervention was about 6.2%/year. It may be necessary to give careful consideration to the prevention of lethal arrhythmic events in MVO-HCM patients, especially those with severe left ventricular hypertrophy.