Outcome of prolonged QRS interval in dilated cardiomyopathy: role of implantable cardioverter-defibrillators on mortality.

Aim: The main objectives of this study were to investigate the relationship between prolonged QRS interval and its prognosis in patients with dilated cardiomyopathy (DCM), and to determine the effects of cardiac pacing with an implantable cardioverter-defibrillator (ICD) on mortality in patients with a QRS width > 150 ms.

Methods: We retrospectively queried the healthcare enterprise data warehouse and the patient medical records from January 2007 to December 2012 for 1453 cases of DCM at a university- affiliated hospital. Of the 1453 cases, 989 patients were included in the final analyses. Primary outcome variable was all-cause mortality.

Results: Of the 989 patients, 20% (n = 198) of the patients had a QRS width > 150 ms. Compared with patients who had a QRS < 120 ms, patients with a QRS > 150 ms had significantly higher rates of death (p < 0.001). Among the subgroup of 198 patients who had a QRS width > 150 ms, survival (84.3%, n = 75) was significantly higher (p < 0.001) in patients with a pacemaker inserted compared with those (45.0%, n = 49) who had not been paced.

Conclusions: Prolonged QRS interval is significantly associated with a higher rate of mortality. However, we believe that cardiac pacing with an ICD in such patients can significantly improve outcomes.