Sustained VT/VF linked to increased mortality after PCI in STEMI patients

6 May 2009

MedWire News: Patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) who develop sustained ventricular fibrillation or tachycardia before or after the procedure have significantly increased 90-day mortality, a study reveals.

Rajendra Mehta (Duke Clinical Research Institute, Durham, North Carolina, USA) and team evaluated the association of ventricular fibrillation (VF) or ventricular tachycardia (VT) and its timing with risk for death at 30 and 90 days in 5745 patients with STEMI undergoing PCI at 296 hospitals in 17 countries.

They report in the Journal of the American Medical Association that VT/VF occurred in 329 (5.7%) patients. The majority of these occurred early (before the end of catheterization, n=205; 64%), and 90% occurred within 48 hours of presentation with STEMI symptoms.

The 90-day mortality rate was significantly higher among patients with any VT/VF compared with those without, at 23.2% versus 3.6%, and an adjusted hazard ratio (HR) of 3.63. Outcomes were particularly worsened among patients with late (after the end of catheterization) VT/VF, with a 90-day mortality of 33.3% (HR=5.59), although still significantly worse for those with early VT/VF,at 90-day mortality of 17.2% (HR=2.34).

Factors associated with late VT/VF were low systolic blood pressure, increased heart rate (>70 beats per minute) and body weight, ST resolution less than 70%, post-PCI Thrombolysis in MI (TIMI) flow below grade 3 and pre-PCI TIMI flow grade 0, and beta-blocker treatment for less than 24 hours.

“Our analysis identified patients who may benefit from closer surveillance int eh intensive care or telemetry unit after the PCI procedure because of the risk for late VT/VF,” the authors write.

“In contrast, because of very low risk for late VT/VF in patients with complete reperfusion, our findings suggest that close monitoring for late VT.VF may not be necessary and these patients may be candidates for early discharge.”

They add that, as most patients with STEMI worldwide are routinely moitored for longer than 72 hours, these findings have the potential to decrease resource use without compromising patient safety when a risk-based strategy of monitoring or early discharge is followed.

JAMA 2009; 301: 1779-1789