Centre for Heart Lung Innovation, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada.
Division of Cardiovascular Surgery, University of British Columbia, St. Paul's Hospital, Vancouver, British Columbia, Canada.
J Thorac Cardiovasc Surg. 2014 May;147(5):1627-33. doi: 10.1016/j.jtcvs.2013.11.043. Epub 2013 Dec 31.
Although it is known that preoperative decreased left ventricular ejection fraction (LVEF) is a risk for morbidity and mortality after cardiac surgery, there are no reliable markers of risk in patients with preserved LVEF. This study examines whether a prolonged QTc interval is associated with adverse outcomes in patients with preoperative LVEF greater than 40% undergoing cardiac surgery.
A retrospective chart review of patients who had cardiac surgery at St. Paul's Hospital in Vancouver, Canada, between 2004 and 2009, who had a preoperative LVEF greater than 40%, was undertaken. We tested for association of preoperative prolonged QTc interval with mortality and morbidity using unadjusted and adjusted analyses.
Five-hundred and fifty-five patients with a preoperative LVEF greater than 40% were included in the study; 496 (89.4%) had cardiopulmonary bypass and the remainder were off pump. Preoperative prolonged QTc was associated with increased mortality at 30 days (P < .01), 90 days (P < .01), and 8 years (P < .01), and these results remained significant after adjusting for the clinical variables significantly associated with mortality (8-year odds ratio, 2.42; 95% confidence interval, 1.34-4.34; P = .003). Similar results were found when the analysis was restricted to the more homogeneous group of patients undergoing on-pump coronary artery bypass (CABG, n = 408). Prolonged QTc was also associated with prolonged intensive care unit stay (P = .02), prolonged hospital stay (P < .01), development of atrial arrhythmias (P = .02), and low cardiac output syndrome (on-pump CABG, P = .02).
In patients undergoing cardiac surgery and a preoperative LVEF greater than 40%, a prolonged QTc interval is associated with increased short-term and long-term mortality and increased perioperative morbidity, and therefore should be considered when assessing risk preoperatively.
尽管已知术前左心室射血分数（LVEF）降低与心脏手术后发病率和死亡率相关，但在 LVEF 正常的患者中，尚无可靠的风险标志物。本研究旨在探讨术前 LVEF 大于 40%的心脏手术患者中，QTc 间期延长是否与不良结局相关。
对 2004 年至 2009 年在加拿大温哥华圣保罗医院行心脏手术且术前 LVEF 大于 40%的患者进行回顾性图表审查。我们使用未调整和调整分析来检验术前 QTc 间期延长与死亡率和发病率的关系。
共纳入 555 例术前 LVEF 大于 40%的患者；其中 496 例（89.4%）行体外循环，其余患者行非体外循环。术前 QTc 间期延长与 30 天（P<.01）、90 天（P<.01）和 8 年（P<.01）死亡率增加相关，且在调整与死亡率显著相关的临床变量后，这些结果仍具有统计学意义（8 年的优势比，2.42；95%置信区间，1.34-4.34；P=.003）。当将分析限制在接受体外循环冠状动脉旁路移植术（CABG，n=408）的更同质患者组时，也得到了类似的结果。QTc 间期延长还与重症监护病房（P=.02）停留时间延长、住院时间延长（P<.01）、房性心律失常（P=.02）和低心输出综合征（体外循环 CABG，P=.02）的发生相关。
在接受心脏手术且术前 LVEF 大于 40%的患者中，QTc 间期延长与短期和长期死亡率增加以及围手术期发病率增加相关，因此在术前评估风险时应予以考虑。
