Acute coronary syndrome (ACS) is associated with high morbidity and mortality in octogenarians. Frequent rehospitalization following the index event, due to cardiac or noncardiac causes are very common in this group. Apart from cardiovascular causes, multimorbidity, age related frailty, dementia and cognitive impairments contribute to increased readmissions. 

This retrospective data analysis study was aimed to evaluate the rate and causes of rehospitalizations in octogenarians following the index event. Retrospective analysis of Electronic Medical Records (Cerner) of octogenarians admitted to our hospital between year 2014and 2017 with a primary diagnosis of acute coronary syndrome (ACS) were analyzed. Patients were treated either by percutaneous coronary intervention (PCI) or conservatively (non-PCI) as per the institutional protocol and as per the decision of treating cardiologist based on patient's clinical status. Patients were followed for further events with a mean follow up of3.5± 2.2 years (1month to 93months). Mid to long term outcome in both groups were analyzed and compared. Causes and rate of re-hospitalization during this period were studied. 

Data of 170 octogenarians admitted with ACS during this period were selected and analyzed for the study. Of these, 52 patients (30.6%) had undergone percutaneous coronary Intervention (PCI) and 114 patients (67%) were treated conservatively (non-PCI). Patients treated conservatively were comparatively older than PCI group (86.1±6.1 vs83.6±4.6years; p=0.0106). No significant difference in gender ratio between the two groups (49.1% female in non-PCI group and 55.8% female in PCI group; p=0.4245). Majority of the patients presented with NSTEMI (97.4% in non-PCI;71.2% in PCI).No significant in-hospital (11.5% vs 17.5%; p=0.3248) mortality differences between non-PCI and PCI groups. One-year all-cause mortality was significantly higher in non-PCI group (34.9% vs. 15.3%; p=0.0072). Subsequently the survival curve started diverging with significantly higher mortality in non-PCI group. During the mid to long-term follow up for 3.5± 2.2 years (1 to 93 months) total mortality was71.1% in non-PCI group and 42.3% in PCI group (p=0.0004). Most deaths were noncardiac in both groups (54.3% vs. 68.2%; p=0.2516). Combination of infection, sepsis and AKI were the most important cause of death in both groups (54.8% vs. 50%; p=0.6938).There was significant difference in the rate of rehospitalizations during the first year of follow up (59.6% in non-PCI vs.42.3% in PCI; p=0.0386). Average number of rehospitalization per patient during the follow up was (6.1 in non-PCI vs. 3in PCI per patient; p<0.0001). No significant difference in rate of rehospitalization after one year.Most common cause of rehospitalization was non-cardiac in both groups (65.7% in non-PCI vs.55.8% in PCI; p=0.0484). Infection with or without sepsis was the most important non-cardiac cause of rehospitalization in both groups (24.7% in non-PCI vs. 27.1% in PCI; p=0.5954). Most common cardiac cause was heart failure (16.3%vs. 17.8%; p=0.6987). ACS (10.2% vs.15.5%; p=0.1121); bleeding/ anemia (6% vs.10.1%; p=0.1254); AKI (3.9% vs. 7.8; p=0.0921); stroke (5.7 vs. 3.9%; p=0.4349) were the other important causes of rehospitalizations and there were no statistically significant differences between groups.

This retrospective data analysis study shows that morbidity and mortality are very high in octogenarians following acute coronary syndrome. Invasive strategy significantly improved the survival in selected patients compared to the conservative treatment strategy. It also reduced the rate of rehospitalizations initially. The initial benefit in rehospitalization rate associated with invasive strategy was not sustained during the long term follow up. This could probably be due to the increasing multimorbidity associated with advancing age.