Efficacy of invasive treatment and the occurrence of cardiac rupture in acute ST-elevation myocardial infarction

Background: Cardiac rupture is a rare but potentially lethal complication of acute myocardial infarction with ST-elevation (STEMI). Primary percutaneous coronary intervention (pPCI) is a preferable treatment method of acute STEMI. Reperfusion at vascular and myocardial levels may be the key parameters determining probability of cardiac rupture. Aim: To analyse the relationship between reperfusion parameters and cardiac rupture occurrence in a group of patients with STEMI treated with pPCI. Methods: Twenty three patients with cardiac rupture were selected out of 2800 patients with acute STEMI hospitalised and treated with pPCI from 2000 to 2007. Free wall or interventricular septum rupture was diagnosed on echocardiography or autopsy. The control group consisted of 255 patients with STEMI and pPCI treatment, but without cardiac rupture. The TIMI flow score was used to assess blood flow in an infarct-related artery (IRA). Myocardial perfusion was evaluated with the use of the myocardial blush grade (MBG) score. Results: Female gender accounted for 47.8% of patients with cardiac rupture. Mean age was 72.9 +/- 4.8 years for women and 64.3 +/- 11.5 years for men. In 12 (52%) patients anterior descending artery was the IRA. Before the pPCI, the average blood flow in IRA was significantly lower in patients with subsequent cardiac rupture (0.41 +/- 0.59) than in the reference group (0.81 +/- 1.15; p < 0.05), and remained lower after pPCI (1.96 +/- 0.93 in comparison to 2.93 +/- 0.36; p < 0.05). Adequate blood flow (TIMI 3) was achieved only in 30.4% (7) of patients with cardiac rupture and in 95.3% (243) of the control group (p < 0.05). Myocardial tissue perfusion, assessed by MBG, was also lower (0.76 +/- 1 vs 1.92 +/- 1.13; p < 0.05). In-hospital mortality in patients with cardiac rupture reached 56.5% (13 subjects) compared to 3 (1.2%) patients in the reference group (p < 0.05). Multivariable analysis confirmed independent effects of lower TIMI and MBG after PCI as well as female gender on the occurrence of cardiac rupture. Conclusions: Poorer blood flow in IRA and worse tissue microvascular perfusion after pPCI are important risk factors of cardiac rupture occurrence in patients with STEMI.