Long-term prognosis after ST-elevation myocardial infarction in patients with preserved and reduced ejection fraction and chronic kidney disease
L Savic, D Simic, R Lasica, G Krljanac, N AntonijevicAbstract
Background
Chronic kidney disease (CKD) and reduced left ventricular ejection fraction (EF) are predictors of adverse outcomes after ST elevation myocardial infarction (STEMI). The combined presence of reduced EF and CKD can lead to development of cardiorenal syndrome which further worsens the prognosis of these patients, especially in the long-term follow-up. The aim of this study is to analyze long-term prognosis in patients with CKD and reduced EF after STEMI.
Method
we included 3114 STEMI patients treated with primary percutaneous coronary intervention and without cardiogenic shock at admission. Reduced predischarge EF (moderately and severely) was defined as value <50%. Kidney function was assessed at hospital admission (before iodine contrast use) using CKD-EPI formula and CKD was defined as the value of estimated glomerular filtration rate (eGFR) <60ml/min/m2. We divided patients into 4 groups according to the presence of preserved or reduced EF and CKD: groups I (preserved EF, no CKD); group II (reduced EF, no CKD); Group III (preserved EF and CKD) and Group IV (reduced EF and CKD). The follow-up period was 8 years.
Results
Reduced EF was present in 1389(41.1%) patients, baseline CKD was present in 1536(49.3%) patients and patients with baseline CKD had predominantly mild and moderate CKD- 1382 patients (90% of all patients with CKD). There were 332 (10.6%) in group I, 750(24.1%) patients in group II, 651(20.9%) patients in group III and 1139(43%) patients in group IV. When analyzing the whole follow-up period, we found that the lowest 8-year mortality rate was in group I (3%) and the highest 8-year mortality rate was in group IV (11.8%); eight year mortality rates in groups II and III were 10.4% and 2.5%, respectively (Figure 1). In the groups II and IV the highest mortality rate was observed in the first year of follow-up, while in groups I and III mortality rate increased stepwise without excess during the whole follow-up period. The causes of 8-year mortality in all four analyzed groups were cardiovascular causes- 89% of all deaths. When analyzing risk for 8-year mortality (Cox regression model) using patients in group I as a reference group we found that the risk for 8-year mortality was highest in the group IV-HR 2.65, 95%CI 1.23-5.36, p=0.012 ; slightly lower risk was observed in the group II- HR 2.54, 95%CI 1.23-5.23, p=0.012,. The risk for mortality was not significantly increased in group III- HR 1.12, 95%CI 0,50-1.69, p=0.787.
Conclusion
Reduced EF (severely and moderated) was a strong risk factor for long-term mortality after STEMI. The presence of CKD further increased the risk for mortality in patients with reduced EF. CKD in patients with preserved EF was not a risk factor for long-term mortality.Figure 1For image description, please refer to the figure legend and surrounding text.