T-peak to T-end interval for prediction of ventricular tachyarrhythmia and mortality in a primary prevention population with systolic cardiomyopathy.

BACKGROUND: The electrocardiographic T-wave peak to T-wave end interval (Tpe) correlates with dispersion of ventricular repolarization (DVR). Increased DVR increases propensity toward electrical reentry that can cause ventricular tachyarrhythmia. The baseline rate-corrected Tpe (Tpec) has been shown to predict ventricular tachyarrhythmia and death in multiple patient populations but not among cardiomyopathic patients undergoing insertion of an implantable cardioverter-defibrillator (ICD) for primary prevention. OBJECTIVE: The purpose of this study was to assess the risk stratification ability of the Tpec in patients with systolic cardiomyopathy without prior ventricular tachyarrhythmia (ie, the primary prevention population). METHODS: We performed prospective follow-up of 305 patients (73% men; left ventricular ejection fraction [LVEF] 23 ± 7%) with LVEF ≤35% and an ICD implanted for primary prevention. Baseline ECGs were analyzed with automated algorithms. Endpoints were ventricular tachycardia (VT)/ventricular fibrillation (VF), death, and a combined endpoint of VT/VF or death, assessed by device follow-up and Social Security Death Index query. RESULTS: The average Tpec was 107 ± 22 ms. During device clinic follow-up of 31 ± 23 months, 82 patients (27%) had appropriate ICD therapy for VT/VF, and during mortality follow-up of 49 ± 21 months, 91 patients (30%) died. On univariable analysis, Tpec predicted VT/VF, death, and the combined endpoint of VT/VF or death (P < .05 for each endpoint). Multivariable analysis included univariable predictors among demographics, clinical data, laboratory data, medications used, and electrocardiography parameters. After correction, Tpec remained predictive of VT/VF (hazard ratio [HR] per 10-ms increase 1.16, P = .009), all-cause mortality (HR per 10 ms 1.13, P = .05), and the combined endpoint (HR per 10 ms 1.17, P = .001). CONCLUSION: Tpec independently predicts both VT/VF and overall mortality in patients with systolic dysfunction and ICDs implanted for primary prevention.

Elevated serum bone morphogenetic protein 4 in patients with chronic kidney disease and coronary artery disease.

Chronic kidney disease (CKD) is associated with increased coronary artery disease (CAD) and coronary artery calcification. We hypothesized that the osteogenic factor, bone morphogenetic protein-4 (sBMP-4), is elevated in subjects with both CKD and CAD. Serum was collected from 79 subjects undergoing diagnostic angiography and stratified according to CAD and CKD status. Subjects with both CAD and CKD had significantly elevated sBMP-4 compared to those with only one or no disease. sBMP-4 continued to be associated with the presence of both diseases after adjustment for other risk factors. To determine if sBMP-4 is associated with coronary artery calcification, we compared coronary artery calcium scores (CAC) to sBMP-4 in 22 subjects. A positive correlation between CAC and sBMP-4 was seen. In conclusion, sBMP-4 is elevated in patients with both CAD and CKD and positively correlates with CAC, suggesting a role for sBMP-4 in the increased CAD seen in CKD patients.

Usefulness of heart rate as an independent predictor for survival after heart transplantation.

It was unclear whether increased heart rate (HR) increased long-term mortality after heart transplantation (HT). The aim of this study was to evaluate whether HR predicted survival after HT. A retrospective analysis of patients who underwent HT at our institution was performed. Ethnicity, gender, date of birth, age at transplantation, length of follow-up after transplantation, cardiac rhythm within 3 months after transplantation, age at death, reason for transplantation, cause of death, and baseline medications after transplantation were recorded. Continuous variables, such as HR, blood pressure, cardiac ejection fraction, presence of allograft vasculopathy, and serum creatinine, were recorded at <3 months, 6 months, and 1 year after HT, then annually to 10 years after HT. Seventy-eight patients with a mean age of 50 +/- 13 years were identified. Mean survival was 8.5 +/- 6.5 years. Of 78 patients, 32 patients had an HR 90 beats/min within 3 months after HT. There was a mean decrease in HR of 6 beats/min during 10 years (p <0.03). Multivariate survival analysis showed that HR >90 beats/min was a significant predictor of early mortality (hazard ratio 2.8, 95% confidence interval 1.5 to 5.1, p <0.0013). Patients with a net increase in HR during 10 years had an increased risk of death compared with patients with no change or a net decrease in HR (hazard ratio 4.7, 95% confidence interval 1.9 to 12.0, p <0.002). No significant differences in cause of death between patients with an HR 90 beats/min existed. In conclusion, HT patients with an HR >90 beats/min within the first 3 months after HT were 2.8 times more likely to die than patients with an HR