Introduction <p>Severely calcified coronary lesions are a common challenge in older percutaneous coronary intervention (PCI) populations. We aimed to investigate in-hospital and 1-year outcomes of octogenarian and nonagenarian patients with heavily calcified coronary lesions treated with rotational atherectomy (RA).</p> Methods <p>Patients who underwent RA at our center were divided into two groups: octogenarians/nonagenarians (age ≥ 80&#xa0;years) (<i>n</i> = 194) and younger counterparts (age &lt; 80&#xa0;years) (<i>n</i> = 591). Patients presented with acute coronary syndrome, and those treated with bare-metal stents were excluded. At 1&#xa0;year, major adverse cardiac events (MACE) were investigated as a composite of cardiac death, spontaneous myocardial infarction (MI), or target lesion revascularization (TLR).</p> Results <p>In-hospital adverse outcome rates were 10.3% in the octogenarian/nonagenarian group versus 13.5% in the younger group (<i>p</i> = 0.266). Notably, the octogenarian/nonagenarian group had numerically higher in-hospital mortality (2.1% vs. 0.5%, <i>p</i> = 0.067). However, after adjusting for potential confounders, in-hospital mortality did not differ significantly between study arms (adj. HR 3.68; 95% CI 0.69–19.5, <i>p</i> = 0.126). At 1&#xa0;year, the octogenarian/nonagenarian group was associated with a higher MACE rate (20% vs. 13%, adj. HR 1.78; 95% CI 1.27–2.50, <i>p</i> = 0.001), which was driven mainly by more cardiac deaths (13% vs. 4%, log-rank <i>p</i> &lt; 0.001). Rates of MI (log-rank <i>p</i> = 0.708) and TLR (log-rank <i>p</i> = 0.333) were comparable between both study arms.</p> Conclusions <p>RA is feasible in octogenarian and nonagenarian patients, with in-hospital adverse outcomes comparable to those of younger patients. Advanced age remains a strong predictor of 1-year MACE, given its inherently higher mortality.</p> <p>Graphical abstract available for this article.</p> Graphical Abstract <p></p>