Frailty and comorbidity burden predict complications after mechanical thrombectomy in Octogenarians.

BACKGROUND

Comorbidity burden and physiological reserve play a critical role in post-stroke outcomes among elderly patients. This study evaluates the predictive utility of commonly used comorbidity and risk indices, including the Charlson Comorbidity Index (CCI), modified Frailty Index (mFI-5, mFI-11), and Risk Analysis Index (RAI, RAI-Rev), in octogenarian patients undergoing endovascular mechanical thrombectomy (EVT) for middle cerebral artery (MCA) stroke.

METHODS

Data were extracted from the National Inpatient Sample (NIS) to identify octogenarian patients (aged 80-89) with MCA ischemic stroke who underwent mechanical thrombectomy. Primary outcomes included in-hospital mortality, while secondary outcomes encompassed procedural complications, non-home discharge, extended hospital stays, and high-cost hospitalization. Receiver operating characteristic (ROC) curve analysis assessed the predictive performance of each index. Multivariate regression models were used to evaluate associations between comorbidity indices and clinical outcomes.

RESULTS

A total of 18,520 octogenarian thrombectomy patients were analyzed. Higher CCI, mFI-5, and mFI-11 scores were significantly associated with increased odds of complications (CCI OR 1.136 [95% CI 1.103-1.170], mFI-5 OR 1.330 [95% CI 1.213-1.459], and mFI-11 OR 1.332 [95% CI 1.237-1.434], respectively; p < 0.001 for all), extended hospital stays (CCI OR 1.151 [95% CI 1.115-1.188], mFI-5 OR 1.272 [95% CI 1.157-1.400], and mFI-11 OR 1.178 [95% CI 1.091-1.272], respectively; p < 0.001 for all), non-home discharge, and higher healthcare costs. CCI was the only evaluated index significantly associated with in-hospital mortality (OR 1.075, 95% CI 1.030-1.121, p = 0.0009) and demonstrated the highest AUC for mortality prediction among included indices (AUC 0.591), though overall discriminative performance remained modest. RAI and RAI-Rev demonstrated limited prognostic utility across evaluated outcomes.

CONCLUSIONS

Comorbidity indices, particularly CCI, mFI-5, and mFI-11, demonstrated stronger associations with post-thrombectomy complications and hospital-related outcomes than age alone in octogenarian MCA stroke patients. However, the modest magnitude of observed associations, particularly for in-hospital mortality, suggests these indices serve as supplementary risk-stratification tools rather than definitive decision-making thresholds. These indices may aid clinical risk stratification for elderly stroke patients undergoing mechanical thrombectomy when interpreted alongside neurological status, imaging, and patient goals of care.