A total of 146 patients were analysed (octogenarians = 73; non-octogenarians = 73). The mean age was 85.2 ± 4.1 years in the octogenarian group and 67.1 ± 5.3 years in the control group (Table 1). The octogenarian group had a higher percentage of females (56% vs 29%, P < 0.005), higher overall comorbidities, a higher CCI score (3.2 ± 2.3 vs 1.7 ± 2.2, P < 0.001), were more likely to require residential care (23% vs 2.7%, P < 0.001) as well as home help (25% vs 0%, P < 0.001), and had worse renal function (eGFR 48.7 ± 19.9 vs 68.1 ± 20.3 mL/min per 1.73 m², P < 0.001).

Octogenarians were less likely to have PCI attempted compared to the non-octogenarians (47% vs 84%, P < 0.001). The rate of symptom onset-to-PCI of < 6 h was significantly lower in octogenarians (16% vs 45%, P < 0.001). The rate of PCI success was high in both groups (91% vs 99%, P = 0.1). Reasons PCI was not attempted in non-octogenarians include: No culprit found (3), embolic event (1), recent CVA (1), known or new triple vessel disease/complex anatomy (2), other comorbidities (5); and in octogenarians: No culprit found (9), embolic event (2), recent CVA (4), known or new triple vessel disease/complex anatomy (13), other comorbidities (11). Octogenarians had a significantly higher overall in-hospital mortality (28% vs 7%, P < 0.005) and 30-d mortality (45% vs 12%, P < 0.001).

The independent predictors of 30-d mortality in octogenarians included age (OR 1.20/year of advancing age, P < 0.01), place of residence (OR = 4.4, P < 0.01 for nursing home), conservative management (No intervention - OR 2.77, P < 0.05), and declining renal function (OR = 0.9, P < 0.05).

The 39 (53%) octogenarians who did not receive PCI were older (86 ± 4.3 years vs 84 ± 3.4 years, P < 0.05) and were more likely to be in residential care (41% vs 3%, P < 0.001), had higher CCI score (3.8 ± 2 vs 2.52 ± 2, P < 0.05) and worse renal function (eGFR 44 ± 16 mL/min vs 54 ± 23 mL/min per 1.73 m²). Type of myocardial infarction was not different as compared to octogenarians who received PCI (Table 2).

Mortality rate was high among octogenarians who presented with STEMI. However, those who were managed conservatively had a higher in-hospital and 30-d mortality (37% vs 18%, P = 0.1; and 59% vs 29%, P < 0.05 respectively).

Independent predictors of intervention in octogenarians included younger age (OR = 0.86, P < 0.05), place of residence (OR = 0.1, P < 0.05 for nursing home), lower CCI (OR = 0.7, P < 0.05), and renal function (OR = 1.03, P < 0.05).

Our study demonstrated that mortality rate amongst octogenarians presenting with STEMI is high in Australian population despite the offered treatment, although much worse when treated conservatively. This appears to be associated with higher overall comorbidities, higher CCI score, wore renal function, and need for residential care or home help (which maybe the indirect measure of overall comorbidities and physical state). These findings are consistent with overseas studies looking at similar age groups[7-9]. Some factors reported to affect the mortality in these studies include heart failure, multiple co-morbidities, cachexia, cognitive state, history of intra-cranial bleeding and pre-hospital physical activity status[10,11]. Furthermore, it has been shown that the elderly are less likely to receive evidence based medical treatment such as aspirin, clopidogrel, beta-blockers, statins or glycoprotein IIb/IIIa inhibitors[7,8]. This may be due to concerns with regards to potential side effects in this age group. Previous studies have also shown that the elderly is associated with a higher rate of PCI failure. However, this is not reflected in our study, likely because the candidates for treatment were carefully selected.

Our study suggested that despite having a higher mortality rate, octogenarians are less likely to have PCI attempted as compared to non-octogenarians. Frailty, co-morbidities and time delays have been shown to contribute to the underuse of invasive therapies. In our study, the proportion of those who received PCI in less than 6 h was significantly lower in the octogenarian group. This might reflect difficulty in decision-making with regards to reperfusion strategy. Atypical clinical presentation is also more common in the elderly and could contribute to time delay as well as the higher prevalence of cardiac failure. In addition, female gender was more prevalent in the octogenarian group. Previous studies have shown that female gender is associated with lower use of invasive therapies, especially in the elderly[12].

Another major finding of our study is that despite a relatively poor prognosis, octogenarians who received primary PCI had a significantly lower 30-d mortality. This however maybe related to the selection bias, a limitation of observational study design. Patients managed conservatively in our study were older, more likely to be in residential care, had a higher CCI score and worse renal function, and this represents a group with higher risk profile. The most common reasons PCI was not performed in the elderly were triple vessel disease/complex anatomy, other co-existing comorbidities and the absence of a clear culprit lesion. There was no significant difference in in-hospital mortality between those managed who received intervention and those managed conservatively. Other factors affecting 30-d mortality included age, place of residence and declining renal function, highlighting the complexity of this patient population.

Our study is not randomized, and therefore limited by selection bias. However, it is an “all comers” registry which reflects “real world” data on management and outcomes of elderly patients who presents with STEMI. A randomised trial in this particular group is not viable. Propensity score matching would be the next best option and requires larger studies. Furthermore, we did not evaluate long term mortality and re-infarction rates, which may provide incremental information and a better picture of the utility of invasive management in this group.

In conclusion, this study is the first Australian report on the outcomes of octogenarians who present with ST-elevation myocardial infarction. This group represents a complex population with multiple medical comorbidities and PCI is challenging, associated with high failure and complication rates. Consequently, mortality is high in this group. However, the detrimental prognosis of conservatively managed octogenarians and relative mortality benefit associated with PCI suggests that revascularization therapy may benefit this age group.

The elderly have an increased risk of acute coronary syndrome. However, there are more likely to be managed conservatively compared to the younger cohort. This is due to concerns regarding procedural complications and success. The elderly is also under-represented in major clinical trials evaluating primary percutaneous coronary intervention (PCI). Recognizing this there have been recent overseas studies evaluating the elderly and primary PCI.

This study is the first to evaluate the characteristics and outcome of octogenarians who presents with ST-elevation myocardial infarction (STEMI) in an Australian setting. The authors also evaluated the outcomes of octogenarians who received primary PCI compared to those that were managed conservatively.

This paper showed that despite poor prognosis among octogenarians who presents with STEMI, primary PCI may offer some benefit, with significantly lower 30 d mortality in the group that received it.

Primary PCI should be considered in octogenarians who presents with STEMI. The patient’s co-morbidities, quality of life and life expectancy should be taken into account when making this decision.

Primary PCI consists of urgent balloon angioplasty (with or without stenting), without the previous administration of fibrinolytic therapy or platelet glycoprotein IIb/IIIa inhibitors, to open the infarct-related artery during an acute myocardial infarction with ST-segment elevation.

This is an interesting and well-written article dealing with care on octagenaries after acute myocardial infarction. The authors have found worse clinical characteristics in octogenaries in comparison with non octagenaries, as well as lower referral for interventional procedures.