Ischemic preconditioning protects right ventricular function in coronary artery bypass grafting patients experiencing angina within 48-72 hours.

BACKGROUND

To test whether ischemic preconditioning (IP) is able to protect the myocardium in recently unstable CABG patients.

EXPERIMENTAL

DESIGN

prospective, randomised, controlled clinical study.

SETTING

University Hospital.

PATIENTS: Forty CABG patients with recent unstable angina were randomised into an IP group (n=20) and a control group (n=20). Subgroup was divided based on the time of the most recent ischemia onset before the operation.

INTERVENTION: The IP group was preconditioned with 2 cycles of 2-min ischemia followed by 3-min reperfusion before cross clamping.

MEASURES: Hemodynamic data were monitored till the 1st POD. Biochemical markers were measured till the 2nd POD.

RESULTS

There were no differences in cardiac index (Cl) and right ventricular ejection fraction (RVEF) in patients experiencing angina within 48 hours prior to operation. The percentage changes in CI and RVEF at 1 hour after declamping were significantly better in the IP group in patients experienced angina within 48-72 hours (106% vs 88% of baseline, p=0.027 and 103% vs 81% of baseline, p=0.023). No difference in postoperative cardiac troponin I (CTnI) and CK-MB was found between the IP and controls in either subgroup.

CONCLUSIONS

IP has a beneficial effect on global and right ventricular hemodynamic functional recovery in unstable CABG patients experiencing angina within 48-72 hours prior to the operation. However, IP has no additional protective effects in unstable CABG patients who experience angina within 48 hours.