Predictors of cardiac mortality in PCI-treated STEMI patients
In patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PPCI), admission Killip classification and creatinine and troponin levels are important cardiac mortality predictors, according to a recent Singapore study.
Using a real-world acute myocardial infarction registry, the present study has “provided the variables and their associated scores that could be incorporated into a risk score to risk-stratify patients and guide duration of hospital stay, short- and medium-term management and follow-up, to improve outcomes in these patients,” said researchers.
Drawing from the Singapore Myocardial Infarction Registry, researchers identified 11,546 STEMI patients who received PPCI. The overall mortality rate was 6.4 percent and the corresponding 30-day and 1-year values were 6.8 percent and 8.3 percent. Majority of the participants (70 percent; n=8,082; median age, 57.6 years; 85.2 percent male) were assigned to the derivation cohort. [Sci Rep 2019;9:10072]
Multivariable logistic regression analysis in the validation cohort identified older age as a significant risk factor for in-hospital (≥80 years vs <40 years; odds ratio [OR], 18.48, 95 percent CI, 2.44–140.17; p<0.001), 30-day (OR, 10.71, 2.47–46.46; p<0.001) and 1-year (OR, 17.26, 4.04–73.63; p<0.001) cardiac mortality.
The same was true for a higher Killip class upon admission (I vs IV; in-hospital: OR, 4.24, 3.11–5.77; p<0.001; 30-day: OR, 3.75, 2.79–5.05; p<0.001; 1-year: OR, 3.27, 2.50–4.27; p<0.001) and cardiac arrest upon admission (in-hospital: OR, 6.61, 4.52–9.65; p<0.001; 30-day: OR, 5.09, 3.52–7.37; p<0.001; 1-year: OR, 4.55, 3.20–6.46; p<0.001).
Elevated creatinine and troponin levels on admission, as well as the lowest left ventricular ejection fraction over the course of hospitalization, were similarly significantly predictive of in-hospital, 30-day and 1-year cardiac mortality (p<0.001 for all).
In comparison, a history of diabetes was only significantly predictive of 1-year cardiac mortality (OR, 1.33, 1.06–1.67; p=0.014), while prior ischaemic heart disease appeared to protect against in-hospital (OR, 0.55, 0.38–0.80; p=0.001) and 30-day (OR, 0.62, 0.44–0.87; p=0.006) cardiac mortality.
The obtained model was tested in the validation cohort of 3,464 patients (median age, 57.9 years; 84.5 percent female). Performance was good overall, resulting in a c-statistic of 0.922 (0.902–0.942) for in-hospital cardiac mortality. The respective values for 30-day and 1-year cardiac mortalities were 0.913 (0.891–0.935) and 0.903 (0.882–0.923).
Moreover, the model only misclassified in-hospital, 30-day and 1-year cardiac mortality cases 14.0 percent, 14.7 percent and 16.2 percent of the time, respectively.
“The potential immediate utility of these predictors is to identify those low-risk patients who could be discharged early,” said researchers. “Secondly, it could potentially be used to identify those at high risk and who would benefit from more aggressive up-titration of their prognostic medications and more frequent follow-ups.”
The obtained model could also be used when counselling patients, helping them better understand their prognoses, they added.