Short- and long-term outcomes depending on electrical dyssynchrony markers in patients presenting with acute heart failure: clinical implication of the first-degree atrioventricular block and QRS prolongation from the Korean Heart Failure registry.

BACKGROUND: Prolongations of PR interval and QRS duration on 12-lead electrocardiogram are associated with atrioventricular and interventricular/intraventricular dyssynchrony, respectively. However, their clinical significance remains unclear in real-world heart failure (HF) population. We assessed whether the presence of first-degree atrioventricular block and/or QRS prolongation (≥120 ms) is associated with worse short- and long-term outcomes in patients with acute HF.

METHODS: The Korean Heart Failure is a nationwide registry of 3,200 consecutive patients presenting with acute HF at 24 centers in South Korea between June 2004 and April 2009. We selected 1,986 patients with sinus rhythm and divided them into 4 groups depending on the presence of first-degree atrioventricular block and/or QRS prolongation; ED_Neither (n = 1,347), ED_PR (n = 217), ED_QRS (n = 329), and ED_Both (n = 93) groups, respectively.

RESULTS: During the median follow-up of 18.2 months, overall death rate (17%, 22%, 20%, and 29%, P < .01) tended to rise with increasing number of electrical dyssynchrony markers. Patients in ED_Both group showed worst outcomes regarding the requirement of invasive managements during the index admission, in-hospital mortality, postdischarge death/rehospitalization, and cardiac device implantation. In time-dependent Cox regression analyses, presence of both PR >200 ms and QRS ≥120 ms was independently associated with in-hospital death (P < .01), postdischarge death/rehospitalization (P = .03), cardiac device implantation (P < .01), and overall death (P < .01).

CONCLUSIONS: A combined analysis of electrical dyssynchrony markers (PR prolongation and QRS widening) might be useful for short- and long-term risk stratifications of patients with acute HF.