Myocardial reperfusion injury may attenuate the benefit of pPCI. In animal models, RIPC mitigates myocardial reperfusion injury.
One hundred patients with anterior ST-segment elevation myocardial infarction and occluded left anterior descending artery were randomized to pPCI聽+ RIPC (n聽= 50) or conventional pPCI (n聽=聽50). RIPC consisted of 3 cycles of 5 min/5 min ischemia/reperfusion by cuff inflation/deflation of the lower limb. The primary endpoint was infarct size assessed by the area under the curve of creatinine kinase-myocardial band release (CK-MB). Secondary endpoints included the following: infarct size assessed by cardiac magnetic resonance delayed enhancement volume; T2-weighted edema volume; ST-segment resolution >50%; TIMI (Thrombolysis In Myocardial Infarction) frame count; and myocardial blush grading.
Four patients (2 RIPC, 2 controls) were excluded due to missing samples of CK-MB. A total of 96 patients were analyzed; median area under the curve CK-MB was 8,814 (interquartile range [IQR]: 5,567 to 11,325) arbitrary units in the RIPC group and 10,065 (IQR: 7,465 to 14,004) arbitrary units in control subjects (relative reduction: 20%, 95% confidence interval: 0.2% to 28.7%; p聽= 0.043). Seventy-seven patients underwent a cardiac magnetic resonance scan 3 to 5 days after randomization, and 66 patients repeated a second scan after 4 months. T2-weighted edema volume was 37 卤 16 cc in RIPC patients and 47 卤 22 cc in control subjects (p聽=聽0.049). ST-segment resolution >50% was 66% in RIPC and 37% in control subjects (p聽=聽0.015). We observed no significant differences in TIMI frame count, myocardial blush grading, and delayed enhancement volume.
In patients with anterior ST-segment elevation myocardial infarction, RIPC at the time of pPCI reduced enzymatic infarct size and was also associated with an improvement of T2-weighted edema volume and ST-segment resolution >50%. (Remote Postconditioning in Patients With Acute Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention [PCI] [RemPostCon]; )