Despite these observations, the authors noted death rates remained similar throughout the study, ranging from 5.3 to 7.3 percent for in-hospital mortality and from 7.8 to 10.9 percent for one-year mortality. They attributed this to more STEMI patients presenting with comorbid heart failure as the study progressed, demonstrating that clinicians are increasingly performing PCI in more severe cases.
Notably, more patients had heart failure upon admission as the study progressed, but fewer developed in-hospital heart failure—either new-onset or persistent HF symptoms—immediately following PCI.
“The increasing frequency of patients with HF at admission imply that pPCI teams are now more willing to treat higher-risk patients and have, at the same time, been able to achieve shorter FTD times,” Chan and colleagues wrote. “Moreover, with the reduction of FTD, there was an increase in the proportion of patients presenting with acute HF whose HF status improved after admission, as well as a decrease in the proportion of patients with worsening HF status after admission, suggesting that reductions in FTD mitigate the risks of HF post-pPCI.”
The authors noted analyses from other national databases also support an association between reperfusion time and mortality at six to 12 months.
“While none of these studies, including ours, can establish a causal link between FTD and late mortality because of their observational nature, they collectively represent data from four independent healthcare systems that support this epidemiological association,” they wrote. “Our study … reaffirmed that mortality benefits from a shortened FTD may not be demonstrated on a population level because of worsening risk profile, but this relationship is clearly demonstrated on the individual patient-specific level.”
Chan et al. said a major limitation of their study was the lack of information on postdischarge care (aside from medications at discharge), which likely influenced late readmission and mortality outcomes.