Prolonged QTc affects short-term and long-term outcomes in patients with normal left ventricular function undergoing...

Area of Science:

• Cardiology
• Cardiac Surgery
• Electrophysiology

Background:

• Preoperative decreased left ventricular ejection fraction (LVEF) is a known risk factor for cardiac surgery outcomes.
• Reliable risk markers are lacking for patients with preserved LVEF undergoing cardiac surgery.

Purpose of the Study:

• To investigate the association between a prolonged QTc interval and adverse outcomes in patients with preoperative LVEF > 40% undergoing cardiac surgery.
• To determine if QTc interval can serve as a predictive marker for mortality and morbidity in this patient group.

Main Methods:

• Retrospective chart review of 555 patients with LVEF > 40% who underwent cardiac surgery between 2004-2009.
• Analysis of the association between preoperative prolonged QTc interval and mortality/morbidity using unadjusted and adjusted models.

Main Results:

• A prolonged QTc interval was significantly associated with increased 30-day, 90-day, and 8-year mortality.
• The association remained significant after adjusting for clinical variables (8-year OR, 2.42; P=.003).
• Prolonged QTc also correlated with longer ICU and hospital stays, atrial arrhythmias, and low cardiac output syndrome.

Conclusions:

• A prolonged QTc interval is a significant predictor of increased short-term and long-term mortality in patients undergoing cardiac surgery with preserved LVEF (>40%).
• This electrophysiological marker is also associated with increased perioperative morbidity.
• The QTc interval should be incorporated into preoperative risk assessments for these patients.