Approximately 50% of heart transplant programs currently employ a strategy of induction therapy (IT) with either interleukin-2 receptor antagonists (IL2RA) or polyclonal anti-thymocyte antibodies (ATG) during the early postoperative period. However, the overall utility of such therapy is uncertain and data comparing induction protocols are limited. The authors searched PubMed, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov through January 2018 for randomized controlled trials (RCTs) or observational controlled studies of IT vs no IT and IL2RA vs ATG. Inverse variance fixed effects models with odds ratio (OR) as the effect measure were used for primary analyses. Main outcomes include moderate and severe rejection, all-cause mortality, infection, and cancer. The authors' search retrieved 2449 studies, of which 11 met criteria for inclusion (8 RCTs and 3 observational case-control studies). Quality of evidence for RCTs was moderate to high. Overall, patients receiving IT had similar risk of moderate-to-severe rejection, all-cause death, infection, and cancer with patients who did not receive IT. The use of IL2RA was associated with significantly higher risk of moderate-to-severe rejection than ATG (OR 3.4; 95% CI 1.4 to 8.1), but similar risk of death, infections, and cancer. The use of IT was not associated with any benefits or harms compared with no IT. Moderate-to-severe rejection may be reduced by ATG compared with IL2RA.

Contrast-induced nephropathy (CIN) is a type of acute kidney injury associated with intravascular administration of iodinated contrast, usually reversible. Contrast agents are an essential component of invasive and noninvasive coronary angiography. These agents have been modified over time to enhance patient safety and tolerability, but adverse reactions still occur. CIN has been variably defined, as a rise in serum creatinine of 0.5 mg/dl, or a 25% increase in serum creatinine above baseline within 24-72 hours after the procedure. The incidence of CIN varies based on the definition used and risk profile of the patients. CIN is rare among patients with normal renal function at baseline. In low-risk patients, CIN occurs in 1-5%, whereas in higher-risk populations, the incidence can be as high as 30%. CIN is also associated with a 5- to 20-fold increased risk of other early adverse events including in-hospital myocardial infarction, target vessel occlusion, and early mortality. The main prevention strategies are adequate intravenous hydration before, during and after the procedure as well as restriction of contrast load with maximum volume approximately no more than three times the serum creatinine clearance. Recent observational and small prospective randomized trials demonstrate the reduction of CIN incidence with HMG-CoA enzyme inhibitors. In this systematic review and meta-analysis we explore the effects of statin administration in prevention of CIN.