What is a question about this article? If the question is unanswerable, say "unanswerable".

Some risk factors for death include age, hemodynamic parameters (such as heart failure, cardiac arrest on admission, systolic blood pressure, or Killip class of two or greater), ST-segment deviation, diabetes, serum creatinine, peripheral vascular disease, and elevation of cardiac markers. Assessment of left ventricular ejection fraction may increase the predictive power. Prognosis is worse if a mechanical complication such as papillary muscle or myocardial free wall rupture occurs. Morbidity and mortality from myocardial infarction has improved over the years due to better treatment.

Prognosis improves after what complication?
unanswerable