Inverse relation between diastolic blood pressure and long-term outcomes in patients undergoing pharmacoinvasive therapy for myocardial infarction: the J-shaped relation in the contemporary era of revascularisation

Abstract

In the thrombolytic era, it was reported that in the presence of significant coronary stenosis, lowering diastolic blood pressure (DBP) below a critical threshold would result in a paradoxical increase in the occurrence of myocardial infarction (MI). We sought to re-evaluate this J-shaped relation in the era of pharmacoinvasive therapy. A total of 182 patients who underwent early (<1 week, mean 2.3 days) coronary angioplasty after thrombolysis were analysed. Thrombolytic agents (streptokinase in 60%, tissue plasminogen activator in 40%) were administered in an average door-to-needle time of 66 min (<=30 min in 43 [24%] patients). A thrombolysis in myocardial infarction (TIMI) 3 flow was achieved in 56% of patients after thrombolysis, and it was enhanced to 92% after angioplasty. During an average follow-up period of 26 +/-13 months, the adverse event (death, re-MI, target vessel revascularisation or stroke) rate was 21%. Older age, low systolic blood pressure and DBP, fast heart rate, high creatine kinase, hypercholesterolaemia, thrombus-laden lesion, baseline TIMI 0-2 flow were associated with higher occurrence of adverse events. After adjusting for the differing clinical and procedural factors, low DBP (odds ratio 1.10, 95% confidence interval 1.01-1.20, P = 0.041), fast heart rate (odds ratio 1.08, 95% confidence interval 1.02-1.14, P = 0.008) and anterior MI (odds ratio 18.98, 95% confidence interval 2.13-169.19, P = 0.008) were all independent predictors of long-term adverse rate occurrence. A low DBP is an independent predictor of long-term adverse event rates in patients undergoing routine early coronary angioplasty after thrombolysis. This suggests that excessive lowering of DBP may not be desirable before complete revascularisation.