Efficacy of a New Accelerated Streptokinase Regime in Acute Myocardial Infarction: A Double Blind Randomized Clinical Trial

The recanalization after thrombolysis as surrogate for clinical outcomes in patients with ST-segment elevation acute myocardial infarction: A systematic review and meta-regression analysis of data from randomized controlled trials

AIMS

Thrombolytic therapy has been known to be effective in reducing clinical outcomes and increasing recanalization rate among patients with ST-segment elevation acute myocardial infarction (STEMI). However, whether post-thrombolysis recanalization could be used as a surrogate for clinical outcomes is unknown.

METHODS

We systematically searched PubMed, EMBASE and the Cochrane Library database to identify randomized controlled trials (RCT) that examined effects of thrombolytic agents in STEMI. Recanalization was defined as TIMI grade 2 or 3 flow. The primary outcome was in-hospital all-cause mortality. Secondary outcomes included in-hospital and 30-day recurrent myocardial infarction (re-MI), composite of death and re-MI, major bleeding and all bleeding. Random-effects meta-regression was used for analysis.

RESULTS

We identified 111 eligible study arms and 52 eligible comparisons from 58 RCTs involving 16 536 patients. Our analyses showed that among study arms recanalization rate was significantly inversely associated with the incidence of in-hospital all-cause mortality (β: -0.07, 95% confidence interval [CI]: -0.13 to -0.02), re-MI (β: -0.09, 95%CI: -0.18 to -0.01) and the composite of death and re-MI (β: -0.17, 95%CI: -0.28 to -0.05), and positively associated with in-hospital all bleeding but not with major bleeding. Among paired comparisons, the difference in recanalization rate was associated with the corresponding difference in incidence of in-hospital all-cause mortality (β: -0.15, 95%CI: -0.28 to -0.01) but the relationship was not significant for any other outcome.

CONCLUSION

Pooled evidence from RCTs suggest the potential use of recanalization as a surrogate for clinical outcomes in evaluating the efficacy of thrombolysis among patients with STEMI.

Fibrinolytic therapy in patients with ST-segment elevation myocardial infarction: Accelerated versus standard Streptokinase infusion regimen

Introduction: Timely fibrinolysis for acute ST-segment elevation myocardial infarction (STEMI) reduces infarct size and hence preserves LV function and reduces mortality. Optimal regimen of streptokinase (SK) infusion in such patients is a matter of interest. The current study aimed to compare efficacy and safety of accelerated SK infusion regimen in patients with STEMI versus the standard one.

Methods: One hundred consecutive STEMI patients were randomly allocated into one of 2 groups: group I (50 patients) who received accelerated SK regimen (1.5 million units over 30 minutes) and group II (50 patients) received standard SK regimen (1.5 million units over 60 minutes). Efficacy was evaluated non-invasively using clinical (chest pain), ECG (resolution of ST segment) and laboratory tests (earlier and higher peaking of cardiac troponin I). Safety was evaluated by assessment of multiple in-hospital adverse events.

Results: Both groups were statistically matched in all baseline criteria. There was a significant difference between both groups regarding each parameter of successful reperfusion in favor of accelerated regimen. When all these parameters were combined, 31 patients (62%) had successful reperfusion in group I versus 19 patients (38%) in group II (P = 0.016). We did not report any significant difference between both groups regarding in-hospital mortality, in-hospital heart failure, major bleeding, hypotension or allergic reaction to SK. Mean pre-discharge ejection fraction was higher in group I than group II (50.9 ± 6.6% versus 47.3 ± 4.6%, P = 0.002).

Conclusion: Accelerated regimen of SK infusion is safe and effective method of reperfusion in patients with STEMI.

Red cell distribution width is a predictor of ST resolution and clinical outcome following thrombolysis in acute ST elevation myocardial infarction

INTRODUCTION

Red cell distribution width (RDW) has been shown to associate with adverse outcomes in various cardiovascular diseases. We aimed to explore the predictive value of RDW for resolution of the ST segment (STR) after thrombolytic therapy in patients with ST elevation myocardial infarction (STEMI).

METHODS

Patients with STEMI with indication for thrombolytic therapy were recruited from a university center between 2013 and 2015. A comprehensive laboratory investigation at the time of admission included measurement of RDW. Following thrombolysis ST segment resolution was assessed after 90 min. A positive response (STR ≥ 50%) was the primary endpoint. Secondary endpoints were major adverse cardiac events (MACE) defined as occurrence of acute heart failure, ventricular dysrhythmia beyond the first 24h, cardiac arrest or death during hospitalization.

RESULTS

A total of 312 patients (271 male) with the mean age of 57.9 ± 12.3 were enrolled. RDW on admission was 14.1 ± 1.0% (range: 11.6-17.7%). STR was seen in 191 cases (61.2%). MACE occurred in 36 (11.5%) patients. The long-term mortality rate was 7.1% during the follow-up period of 7.7 ± 3.2 months. Even after adjusting for co-morbid conditions, in multivariate model, baseline RDW, independently predicts STR (RR=2.46, 95% CI 1.32-4.57, P=0.005) and in hospital occurrence of MACE (RR=3.17, 95% CI 1.23-8.46, p=0.017). The cut-off values for RDW in predicting STR and MACE were 14.2% and 14.4%, respectively.

CONCLUSION

An elevated baseline RDW could predict adverse outcomes and response to thrombolytic therapy in patients with STEMI. This extends our knowledge about RDW value in prognostication.

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

BACKGROUND

Larger 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.

METHODS

Patients 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) 90minutes 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.

RESULTS

STR≥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 8.2fL in predicting STR and MACE. Patients with MPV ≥8.2fL 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.

CONCLUSION

Higher 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.