Cynthia D. Thomas

Prolonged QTc Interval and High B-Type Natriuretic Peptide Levels Together Predict Mortality in Patients With Advanced Heart Failure

Background—The role of QTc interval prolongation in heart failure remains poorly defined. To better understand it, we analyzed the QTc interval duration in patients with heart failure with high B-type natriuretic peptide (BNP) levels and analyzed the combined prognostic impact of prolonged QTc and elevated BNP. Methods and Results—QTc intervals were measured in 241 patients with heart failure who had BNP levels >400 pg/mL. QT interval duration was determined by averaging 3 consecutive beats through leads II and V4 on a standard 12-lead ECG and corrected by using the Bazett formula. QTc intervals were prolonged (>440 ms) in 122 (51%) patients and normal in 119 (49%). The BNP levels in these 2 groups were not significantly different (786±321 pg/mL in the prolonged QTc group versus 733±274 pg/mL in the normal QTc group, P =0.13). During 6 months of follow-up, 46 patients died, 9 underwent transplantation, and 17 underwent left ventricular assist device implantation. The deaths were attributed to pump failure (n=24, 52%), sudden cardiac death (n=18, 39%), or noncardiac causes (n=4, 9%). Kaplan-Meier survival rates were 3 times higher in the normal QTc group than in the prolonged QTc group (P <0.0001). On multivariate analysis, prolonged QTc interval was an independent predictor of all-cause death (P =0.0001), cardiac death (P =0.0001), sudden cardiac death (P =0.004), and pump failure death (P =0.0006). Conclusions—Prolonged QTc interval is a strong, independent predictor of adverse outcome in patients with heart failure with BNP levels >400 pg/mL.

Outcomes in patients with low left ventricular ejection fraction after heart transplantation.

OBJECTIVES Low left ventricular ejection fraction (EF) after heart transplantation (HT) is considered an ominous sign. We reviewed our database in order to determine outcomes in patients with low EF after HT and to identify a subset of patients who would benefit from immediate retransplantation. METHODS We identified 825 patients who underwent HT at our institution between December 1983 and July 1999. Of these, 81 patients (70 men, 11 women; age, 48+/-12 years) had low (<35%) EF as determined by radionuclide ventriculography. Post-transplantation survival; duration of low-EF episodes (>2 years vs. <2 years); and incidence of transplant rejection, infection, and transplant coronary artery disease (CAD) were determined for these patients. RESULTS On average, low EF developed 800+/-1029 days after HT and lasted 550+/-756 days until improvement, repeat HT, or death of the patient. Actuarial survival was 79% at 1 year, 55% at 3 years, and 46% at 5 years. Shorter (<2-year) episodes of low EF tended to have an earlier onset than prolonged (>2-year) episodes (656 days vs. 1341 days) (P=0.014). Patients with prolonged episodes (n=17) survived longer than patients with shorter episodes (n=64) (2247 days vs. 1266 days) (P=0.002). The incidence of hemodynamically significant rejection was lower in the prolonged low-EF group (6% [1/17] vs. 26% [17/64]) (P=0.03). The incidence of infection (31% vs. 53%) and incidence of transplant CAD (47% vs. 39%) did not differ significantly between the prolonged and shorter low-EF groups. CONCLUSIONS Low EF after HT, especially with later onset, is not associated with poor survival and is not related to hemodynamically significant rejection. These data further indicate that the presence of low EF even in the setting of CAD is not by itself an indication for repeat HT.