One-year major adverse cardiovascular events among same-day discharged patients after primary percutaneous coronary intervention at a tertiary care cardiac centre in Karachi, Pakistan: a prospective observational study

OBJECTIVE: Knowledge regarding the short-term outcomes after same-day discharge (SDD) post primary percutaneous coronary intervention (PCI) is lacking. In this study, we evaluated 1-year major adverse cardiovascular events (MACE) among SDD patients after primary PCI. DESIGN: 1-year follow-up analysis of a subset of patients from an existing prospective cohort study. SETTING: Tertiary care cardiac hospital in Karachi, Pakistan. PARTICIPANTS: Consecutive patients, from August 2019 to July 2020, with ST segment elevation myocardial infarction who had undergone primary PCI with SDD (within 24 hours) after the procedure by the treating physician and with at least one successful follow-up up to 1 year. OUTCOME MEASURE: Cumulative MACE during follow-up at the intervals of 1 week, 1 month, 6 months and 1 year. RESULTS: 489 patients were included, with a gender distribution of 83.2% (407) male patients and a mean age of 54.58±10.85 years. Overall MACE rate during the mean follow-up duration of 326.98±76.71 days was 10.8% (53), out of which 26.4% (14/53) events occurred within 6 months of discharge and the remaining 73.6% (39/53) occurred between 6 months and 1 year. MACE was significantly higher among patients with a Zwolle Risk Score (ZRS) ≥4 at baseline, with an incidence rate of 21.9% (16/73) vs 8.9% (37/416; p=0.001) in patients with ZRS≤3 (relative risk 2.88 (95% CI 1.5 to 5.5)). CONCLUSION: A significant burden of short-term MACE was identified among SDD patients after primary PCI; most of these events occurred after 6 months of SDD, mainly among patients with ZRS≥4. A systematic risk assessment based on risk stratification modalities such ZRS could be a viable option for SDD patients with primary PCI.