Survival benefits of primary angioplasty over thrombolysis after adjustment for percutaneous transluminal coronary angioplasty related time delay

Time to treatment remains a critical determinant of outcome after acute myocardial infarction regardless of the strategy of reperfusion used. We investigated the relationship between primary angioplasty (PTCA)-related delay and the benefits of PTCA, by reviewing the results of randomized trials comparing PTCA with thrombolytic therapy (Rx). The SHOCK trial was not considered in our analysis, Akhras’s trial was excluded because the full data set was not available. DANAMI 2 study was considered as two separated substudies (invasive and referral centers). We calculated the following: PTCA - related delay = median “door to balloon” time – median “door to needle” time Survival benefit= 30 day mortality after Rx – 30 day mortality after PTCA. Relationship between delay and benefit was assessed by linear regression. Reported PTCA - related delay ranged from 7 to 104 minutes, while absolute survival benefit ranged from –4 (favoring Rx) to 15 (favoring PTCA). The survival benefit decreased as the PTCA-related delay increased (figure). After the exclusion of AIR PAMI trial (longest delay and high risk patients) equivalence of survival rates between PTCA and Rx was reached for a PTCA related delay of 63 minutes: change in benefit per 10-minutes delay was 1 % (P=0.01). In clinical trials with short PTCA-related delays, PTCA produced better outcomes, while trials with longer delays favored Rx. At experienced institutions and for high risk patients, however, PTCA is probably still preferable, even when delay is longer.