Remote ischemic preconditioning in elderly patients with acute myocardial infarction and transient ischemic attack: a...

Elderly patients who experience acute myocardial infarction (AMI) in temporal proximity to transient ischemic attack (TIA) carry a high inflammatory burden and a disproportionate risk of recurrent cardio-cerebrovascular events. Remote ischemic preconditioning (RIPC) has been hypothesized to provide systemic protection through neurohumoral and immunomodulatory pathways, but clinical data in this dual-organ ischemia phenotype are limited.

We performed a single-center retrospective cohort study (2018-2023) of patients aged ≥60 years with AMI complicated by neurologist-adjudicated TIA. Patients received guideline-directed care with or without adjunctive RIPC per treating physician judgment. The RIPC protocol consisted of four cycles of 5-min brachial cuff inflation (200 mm Hg or ≥20 mm Hg above systolic pressure) and 5-min deflation, twice daily for 14 days, initiated within 24 h when feasible. The primary endpoint was 12-month major adverse cardiac and cerebrovascular events (MACCE). Time-to-event analyses included Kaplan-Meier estimates and Cox models; the multivariable model adjusted for age, sex, diabetes, left-ventricular ejection fraction (LVEF), log_e interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), and ACE-inhibitor therapy.

Of 382 patients screened, 103 were analyzed (RIPC, 48; control, 55). Baseline characteristics were well balanced (all P ≥ 0.50). RIPC was initiated within 24 h in 85.4% of treated patients; adherence averaged 86.0 ± 12.0% of planned cycles. At 12 months, MACCE occurred in 29.2% of RIPC patients and 49.1% of controls (log-rank P = 0.033). The unadjusted hazard ratio (HR) for MACCE with RIPC vs. control was 0.593 [95% confidence interval (CI), 0.367-0.958]; the multivariable Cox model yielded an adjusted HR of 0.725 (95% CI, 0.545-0.964; P = 0.026). Component analyses were directionally concordant, with lower cumulative incidence of combined cardiac events [25.0% vs. 40.0%; unadjusted HR, 0.628 [95% CI, 0.402-0.981]; adjusted HR, 0.715 [95% CI, 0.506-1.011]] and combined cerebrovascular events [10.4% vs. 21.8%; unadjusted HR, 0.547 [95% CI, 0.308-0.972]; adjusted HR, 0.703 [95% CI, 0.491-1.007]]. In multivariable analyses, higher baseline IL-6 (per pg/mL, HR, 1.032; 95% CI, 1.006-1.058; P = 0.015) and hs-CRP (per mg/L, HR, 1.026; 95% CI, 1.007-1.046; P = 0.008) independently predicted MACCE, as did older age (per year, HR, 1.049; 95% CI, 1.009-1.091; P = 0.017), and ACE-inhibitor therapy was associated with a lower risk of MACCE (HR, 0.714; 95% CI, 0.583-0.973; P = 0.035). Subgroup analyses showed no significant treatment-by-subgroup interactions.

In an elderly cohort with AMI complicated by TIA, adjunctive RIPC was associated with a lower 12-month risk of MACCE after adjustment for clinical and inflammatory covariates, with consistent directional benefits across cardiac and cerebrovascular components and a favorable safety/adherence profile. Baseline IL-6 and hs-CRP were independent determinants of risk, and was consistent with an inflammation-linked pathobiology in which conditioning-based strategies warrant prospective evaluation.