The main findings of the present analysis can be summarized as follows:

1.

RA is feasible in octogenarian and nonagenarian patients, with acute in-hospital adverse outcomes non-significantly different compared to those in the younger population.

2.

Advanced age remains a strong predictor of 1-year MACE due to inherently higher mortality rates.

Understanding the safety and efficacy of RA in octogenarian and nonagenarian patients is increasingly relevant, with the global trend of an aging population. To the best of our knowledge, this is the largest study to investigate acute, and mid-term clinical outcomes of RA-facilitated PCI in an octogenarian/nonagenarian population.

The octogenarians/nonagenarians in our study demonstrated a significantly higher burden of comorbidities. These characteristics reflect the well-documented challenges associated with advanced age and align with previous reports underscoring the complexity of coronary disease in this population [18, 19].

Despite clinical challenges in this age group, we found in-hospital adverse outcome rates not significantly different compared to younger patients, consistent with findings from multicenter registries and observational studies reporting procedural success rates exceeding 90% in older populations undergoing PCI with RA [20, 21]. In our analysis, the in-hospital mortality rate was numerically higher in the octogenarian/nonagenarian group; however, the difference was not statistically significant after adjustment for clinical confounders. Notably, in-hospital mortality events were infrequent, and despite the use of a propensity score adjusted multivariate regression, the adjusted estimate showed wide confidence interval, reflecting considerable uncertainty. Therefore, the absence of statistical significance in our case should not be interpreted as proof of no difference; larger studies are needed to more precisely quantify short-term safety in this population.

Advanced age per se was not found to significantly increase PCI procedural risk if patients were carefully selected and treated with contemporary techniques [22]. This is also in line with current literature demonstrating acceptable overall safety of RA in older patients, with major complications such as coronary perforation or acute vessel closure reported in < 2% of procedures [23]. Moreover, elective RA and operator experience were found to contribute to improved procedural efficiency and outcomes in this high-risk population [24]. RA in our analysis was used electively in 66.9% of the whole study population.

Our findings are also consistent with reports from a high-volume center demonstrating similar in-hospital and 1-year outcomes in generally high-risk patients (low LVEF, prior CABG, higher admission glucose level, and higher EuroSCORE II and Syntax Score) undergoing RA, compared with low-risk patients [25].

Although procedural success is achievable in advanced age as previously reported, long-term outcomes remain influenced by baseline clinical status and comorbidities [26, 27]. At 1-year follow-up, we found that the rate of MACE was significantly higher among octogenarian/nonagenarian patients, mainly driven by increased cardiac mortality. This could be linked to abundant clinical comorbidities in the octogenarian/nonagenarian cohort that are known to be associated with increase death rates [27]. Moreover, the more frequent LM disease and/or bifurcation lesions may add to the mortality risk [28, 29]. It is worth mentioning that advanced age is generally considered as the strongest risk for cardiac mortality [30, 31]. In our analysis, spontaneous MI and TLR rates were comparable between study groups. The absence of excess TLR argues against late RA- or stent-related complications as the dominant mechanism, particularly given the predominant use of new-generation DES and a uniform RA strategy across groups. These findings suggest that long-term outcomes in octogenarian and nonagenarian patients undergoing complex PCI may be more strongly influenced by underlying comorbidity and disease progression than by procedural factors alone, underscoring the need for intensified post-discharge surveillance and tailored secondary prevention strategies [32].

While data on completeness of revascularization were not systematically collected, the feasibility and clinical benefit of more aggressive or alternative revascularization strategies in older patients remain uncertain. Moreover, hybrid approaches or surgical revascularization are often not options in this population due to advanced comorbidity and prohibitive surgical risk [18, 19].

Managing older patients with CAC requires careful, tailored approaches [3, 4], including detailed pre-procedural assessment and frailty evaluation, as well as treatment in experienced centers [2]. The focus should extend beyond survival to improving symptoms and quality of life, balancing procedural efficacy with minimizing complications to optimize outcomes in this vulnerable group [2, 32].

Clinical Implications

The present study reinforces the notion that RA is a viable adjunctive strategy for PCI in octogenarians and nonagenarians, with procedural and in-hospital outcomes non-significantly different compared to younger patients. However, our data also highlight the ongoing challenge of long-term elevated cardiac mortality. This underscores the importance of individualized risk assessment, especially in patients with significant renal dysfunction, LM disease, or frailty—factors that may compound long-term risk regardless of procedural success. Furthermore, our findings support the need for comprehensive follow-up strategies and potentially more aggressive secondary prevention in this cohort. Interventions such as tailored cardiac rehabilitation, vigilant monitoring for heart failure and arrhythmias, and close management of comorbidities may play an essential role in improving long-term prognosis.

Study Limitations

This study is subject to some limitations. First, its retrospective design inherently introduces biases and confounding factors that cannot be fully controlled. As age defines the exposure groups, the propensity score was used as a risk-adjustment tool for in-hospital mortality rather than a causal balancing mechanism; therefore, the reported estimates represent conditional associations rather than the total causal effect of age. The low number of outcome events may limit statistical power despite the use of an adjustment strategy. Second, the study cohort was clinically heterogeneous, encompassing a broad spectrum of diagnoses and varying clinical presentations. Nonetheless, this reflects real-world clinical practice. Third, the study spanned over a long period of time, during which substantial advancements occurred in PCI technologies, procedural techniques, and operator experience. However, this temporal evolution was paralleled by increasing disease burden and lesion complexity. Despite these limitations, the large patient cohort was intended to assess the feasibility, safety, and efficacy of RA in very high-risk octogenarians under real-world conditions.