Remote ischemic preconditioning in isolated valve intervention. A pooled meta-analysis

Objective: Recent studies have shown no benefits from remote ischemic preconditioning (RIPC) in patients undergoing coronary artery bypass surgery. One possible explanation is that given previous exposure to angina and ischemia/reperfusion injury these patients, may be already 'naturally preconditioned'. The role of RIPC in a context of isolated valve intervention, both surgical and particularly transcatheter is less clear and remains under investigated, with few high-quality studies.

Methods: A systematic literature review identified 8 candidate studies that met the meta-analysis criteria. We analyzed outcomes of 610 subjects (312 RIPC and 298 SHAM) with random effects modeling. Each study was assessed for heterogeneity. The primary outcome was the extent of periprocedural myocardial injury, as reflected by the area under the curve for serum troponin concentration. Secondary endpoints included relevant intra- and post-operative outcomes; sensitivity and high-quality subgroup analysis was also carried out.

Results: Six and two studies reported the effect of RIPC in surgical and transcatheter valve intervention. There was a significant difference between-group in terms of periprocedural Troponin release (standardized mean difference (SMD: 0.74 [95% CI: 0.52; 0.95], p = 0.02) with no heterogeneity (χ² 2.40, I² 0%, p = 0.88). RIPC was not associated with any improvement in post-operative outcomes. No serious adverse RIPC related events were reported.

Conclusions: RIPC seems to elicit overall periprocedural cardioprotection in patients undergoing valvular intervention, yet with no benefit on early clinical outcomes.