Background: Elderly patients hospitalised for congestive heart failure (CHF) due to myocardial infarction (MI) have very poor prognosis, particularly if CHF symptoms are caused by left ventricular (LV) systolic dysfunction. Early invasive strategy is considered the best method of preventing post-MI LV dysfunction. The clinical impact of early invasive strategy on prognosis in elderly patients with acute MI has yet to be completely defined because of the poor enrolment of elderly patients in large randomised trials.
Aim: To asses whether treatment of acute MI in patients aged >65 years using percutaneous coronary intervention (PCI) results in significantly better long-term cardiovascular performance in comparison with conservative treatment (CT).
Methods: Our study involved 90 MI patients who underwent diagnostic spiroergometry: 40 patients (mean age 73 years) treated conservatively and 50 (mean age 71 years) by PCI. Echocardiographic examinations and spiroergometric tests were performed at 3-, 6- and 12-month follow-up. Plasma NT-proBNP levels were measured on admission and at 6- and 12-month follow-up.
Results: Echocardiographic and spiroergometric parameters were significantly better in PCI patients in each of the analysed periods and showed significant improvement throughout follow-up (the largest between months 3 and 6). In the CT patients these parameters showed significant improvement only between months 3 and 6. After one year, studied parameters were better in PCI patients (LVESD: 3.1±0.4 vs. 3.5±0.6 cm; p <0.001, LVEF: 62.8±6.6 vs. 55.8±8.3%; p <0.001, LVEDD: 4.9±0.4 vs. 5.1±0.5 cm; p=0.03, duration of exertion: 578±73 vs. 528±108 s; p=0.011, METS: 6.2±1.0 vs. 5.7±1.1; p=0.002, peak VO₂: 22±3.4 vs. 20.3±3.4 ml/kg/min; p=0.02, VE/VCO₂: 29.1±4.4 vs. 33.3±4.7; p <0.001, VE/VCO₂ slope: 23.2±4.7 vs. 27.5±5.1; p <0.001). The groups did not differ in peak VO₂ expressed as peak VO₂ % predicted and plasma NT-proBNP levels. Over the whole follow-up period NT-proBNP levels were negatively associated with LVEF, peak VO₂ and MET, and positively with LVESD and LVEDD recorded at 3 months. In each of the analysed periods spiroergometric parameters significantly correlated with echocardiographic indices recorded at 3 months.
Conclusions: Early PCI for acute MI in patients aged >65 years results in significantly better long-term cardiovascular performance than conservative treatment. The patients showed the most significant improvement in LV performance and exercise capacity between months 3 and 6.