Prognostic significance of nonsustained ventricular tachycardia identified postoperatively after coronary artery bypass surgery in patients with left ventricular dysfunction.
BACKGROUND
Nonsustained ventricular tachycardia (NSVT) occurs frequently in the postoperative period (< or = 30 days) after coronary artery bypass graft (CABG) surgery, a setting where many factors may play a role in its genesis. The prognosis of NSVT in this setting in patients with left ventricular (LV) dysfunction is unknown. This study was designed to assess its significance.


RESULTS
We compared the outcome of untreated patients enrolled in the Multicenter Unsustained Tachycardia Trial with coronary artery disease (CAD), LV dysfunction, and NSVT identified postoperatively after CABG (n = 228; mean age 67 years, 84% males) versus nonpostoperative settings (n = 1,302; mean age 66 years, 85% males). Sustained monomorphic ventricular tachycardia was induced in 27% and 33% (P = 0.046) of patients with postoperative and nonpostoperative NSVT, respectively. The 2- and 5-year rates of arrhythmic events were 6% and 16%, respectively, in postoperative patients versus 15% and 29% in nonpostoperative patients (unadjusted P = 0.0020, adjusted P = 0.0082). The 2- and 5-year overall mortality rates were 15% and 36%, respectively, for postoperative patients versus 24% and 47% for nonpostoperative patients (unadjusted P = 0.0005, adjusted P = 0.027). Patients whose NSVT was identified early (<10 days) versus late (10-30 days) after CABG had significantly lower 2- (13% vs 23%) and 5-year (30% vs 52%) mortality rates (unadjusted P = 0.024, adjusted P = 0.018).


CONCLUSIONS
In this population of patients with CAD and LV dysfunction, the occurrence of postoperative NSVT, especially within 10 days after CABG, portends a far better outcome than when it occurs in nonpostoperative settings. This suggests that in a such setting, NSVT represents a less specific risk factor for future events and should be considered when assigning risk and treatment of similar patients.
Pires
Luis A
LA
Department of Medicine, St John Hospital and Medical Center and Wayne State University School of Medicine, Detroit, Michigan 48302, USA. luis.pires@stjohn.org
Hafley
Gail E
GE
Lee
Kerry L
KL
Fisher
John D
JD
Josephson
Mark E
ME
Prystowsky
Eric N
EN
Buxton
Alfred E
AE
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000150:complications / Q000453:epidemiology / Q000601:surgery; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000453:epidemiology / Q000601:surgery*
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors