Lytic failure in the current pharmacointensive ST-elevated acute myocardial infarction care

Abstract

Thrombolysis remains a very acceptable reperfusion option for ST-elevated acute myocardial infarction (STEMI); however, it fails relatively frequently and unpredictably. To investigate correlates of lytic failure (according to the standard ST resolution criterion) in current pharmacointensive STEMI care (dual antiplatelets with antithrombin), we analyzed retrospectively clinical data and echocardiographic left ventricular systolic function before initiation of reperfusion treatment in Killip I-III STEMI patients admitted to our 'spoke' intensive cardiac care unit between 1 January and 31 December 2010. Of the 53 STEMI patients enrolled, 28% failed thrombolysis. Patients who did not reperfuse were less frequently active smokers (P < 0.05, odds ratio 4.33) and had a higher prevalence of hemodynamic instability [heart rate/SBP (i.e. shock index) >0.75; P < 0.05, odds ratio 13.45) and left ventricular systolic dysfunction (ejection fraction <45%; P < 0.005, odds ratio 11.14). In an exploratory multivariable logistic regression analysis, those variables were the only discriminators independently associated with lytic failure (adjusted odds ratio 8.74, 230.10, and 18.22, respectively, all P < 0.05). Moreover, the combined variables had a high accuracy for prediction of failed thrombolysis (all discriminators positive, 99% specificity and 83% positive predictive value). Our pilot study indicates that thrombolysis still fails in about one-third of STEMI patients despite the current pharmacointensive approach and suggests that failed ST resolution might be independently associated with nonsmoking habit and pretreatment hemodynamic instability and left ventricular systolic dysfunction. Larger trials are needed to verify the potential clinical implications of our preliminary observation.