AIM To assess the predictive value of index of microcirculatory resistance (IMR) for left ventricular recovery in patients undergoing pharmacoinvasive strategy for st-segment elevation myocardial infarction (STEMI).
METHODS The index of microcirculatory resistance was assessed following percutaneous coronary intervention in 38 STEMI patients who were initially treated with thrombolysis. Other markers of microvascular functions such as coronary flow reserve (CFR), TIMI flow grade, corrected TIMI frame count (cTFC) and ST-segment resolution and markers of mycardial injury were also recorded. All indices were evaluated against 3-month post-operation left ventricular function, size of heart infarction and recovery.
RESULTS The pharmacoinvasive strategy achieved a good myocardial perfusion, with TIMI blood flow level 3 in 90% of the patients, TIMI blood flow level 2 in only 10% of the patients and no TIMI blood flow level 1 and 0. Postoperative IMR level was negatively correlated with LVEF 3 months after operation (r=-0.419, P<0.01). Taking 3-month post-operation recovery of left ventricular heart function as the dependent variable and possible factors and the above indicators as independent variables into the binary logistics regression model, only IMR could be used as the predictor (P<0.01), with OR value 1.263 (95% CI 1.059- 1.507). The cutoff point of IMR was 40.5, with prognostic sensitivity of 90% and specificity of 65%.
CONCLUSION IMR has a good value in assessing the 3-month post-operation prognosis of STEMI patients treated with thrombolysis combined with PCI.
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