Mean platelet volume is a predictor of ST resolution following thrombolysis in acute ST elevation myocardial infarction

- Thrombolysis is a mode of treatment of STEMI where primary coronary intervention is not suitable.
- ST segment resolves in response to thrombolysis as the coronary occlusion reverses.
- The response of 50% is considered significant.
- Larger mean platelet volumes are associated with a poor ST response following thrombolysis.

BackgroundLarger mean platelets volumes (MPV) are thrombogenic and frequently seen after ST-segment elevation myocardial infarction (STEMI). This study aimed to examine the association of MPV and resolution of ST-segment after thrombolysis in STEMI patients as and its impact on clinical outcome.MethodsPatients presenting to the emergency department with the diagnosis of first STEMI and were referred to thrombolysis were screened. Patients with ≥ 50% ST-segment resolution (STR) 90 minutes after thrombolysis were assigned as “Responder” and those with < 50% STR were assigned as “Non-Responders”. Demographic, clinical comorbidities and risk factor were recorded along with and angiographic data. In-hospital occurrence of major adverse cardiac events (MACE), including acute heart failure (AHF), reinfarction and death were investigated. Additionally, the patients were followed for 6 additional months after their discharge from the hospital.ResultsSTR ≥ 50% was seen in 60.2% of patients after thrombolysis. Responders had significantly lower MPV (P = 0.001) and the critical MPV values were 8.0 femtoliter (fL) and 8.2 fL in predicting STR and MACE. Patients with MPV ≥ 8.2 fL had lower probability of STR and higher rates of AHF (P < 0.001), and MACE (P = 0.001) compared to the patients with lower platelet volume. In multivariate regression, MPV was an independent predictor of STR (P < 0.001) as well as MACE (HR = 4.8, 95% CI of 1.8-12.4; P = 0.001). Triple vessel disease was another independent factor that predicted MACE.ConclusionHigher MPV's at admission were associated with lower STR and higher occurrence of major adverse cardiac events in patients receiving thrombolytic therapy for first time STEMI.