Non-ST-elevation infarction, the stepchild of interventional myocardial salvage: experience of a single institute

Abstract

The diagnosis of acute myocardial infarction is based on ECG abnormalities besides to chest pain and dyspnea. It is caused by myocardial hypoperfusion, in most patients due to severe coronary artery narrowing or occlusion, but it can also occur without visible coronary artery changes. The non-ST-elevation form (NSTEMI) is usually associated with less complaints compared to the ST-elevation form (STEMI), the ECG changes are not so typical, so its recognition is more difficult in the early stage. Possibility of myocardial cell damage reduction is the restoration of perfusion with coronary intervention. To investigate how much time elapses in acute NSTEMI from the onset of the complaint to the opening of the coronary vasodilator balloon. From 3733 acute coronary interventions performed in NSTEMI between 01. 01. 2016 and 12. 31. 2020, in 1376 patients who underwent percutaneous intervention for the first time, the onset of the complaints, the date of the first medical contact and opening of the balloon, as well as the 30-day or 1-year mortality were known. The median values of the time differences and the mortality data were compared with the similar data of 1718 STEMI patients of this period. The median times were given in hours:minutes, incidence in percent, a two-sample t-test was calculated for the comparison of mortality data. In NSTEMI, the median time between the first medical contact (5:35 vs. 2:05 h:min) and PTCA balloon opening (18:12 vs. 4:05 h:min) was longer compared to the onset of the complaint as in STEMI. Within 2 hours, 21.3% of NSTEMI patients reached the first medical contact and 1.2% had the PTCA balloon opened, in STEMI this ratios were 48.7% and 11.7%. Within 4 hours, these were in NSTEMI 36.3% and 6.1%, in STEMI 64.1% and 46.8%. The 30-day mortality rate in NSTEMI was lower than in STEMI (5.9% vs. 7.9%, p = 0.03), the 1-year rate was higher (16.1% vs. 12.5%, p = 0.004). In 554 primarily admitted patients who met the study criteria, the median P-B time intervals were shorter (10:55 h:min), the mortality data showed a mild but statistically insignificant difference (5.6% at 30 days, 13.9% at 1 year). Based on the 1-year mortality data, NSTEMI cannot be considered less harmful compared to STEMI. After the onset of hypoperfusion, myocardium necrosis proportional to the elapsed time increases the likelihood of subsequent heart failure. For this reason, it seems advisable for patients to reach the intervention center earlier than at present due to the invasive diagnostic and therapeutic options. Orv Hetil. 2023; 164(47): 1865-1870.