Effects of intravenous hydration on risk of contrast induced nephropathy and in-hospital mortality in STEMI patients undergoing primary percutaneous coronary intervention: a systematic review and meta-analysis of randomized controlled trials

Abstract

Background: The role of intravenous hydration at the time of primary percutaneous intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) remains unclear. Guidelines are vague, supported by low level evidence, and hydration is used less often than other clinical settings.To perform a systematic review and meta-analysis of all randomized controlled trials assessing intravenous hydration compared with non-hydration for prevention of contrast induced nephropathy (CIN) and In-hospital mortality in patients with STEMI undergoing primary PCI.

Methods: Medline, EMBASE and the Cochrane Register were searched to September 2018. Included studies reported the incidence of CIN, In-hospital mortality, requirement for dialysis and heart failure. Relative risks with 95% confidence intervals (CIs) for individual trials were pooled using a random effects model.

Results: Three moderate quality trials were identified including 1074 patients. Overall, compared with no hydration, intravenous hydration significantly reduced the incidence of CIN by 42% (RR 0.58; 95% CI: 0.45 to 0.74, p < 0.001). The estimated effects upon all-cause mortality (RR 0.56; 95% CI: 0.30 to 1.02, p = 0.057) and the requirement for dialysis (RR 0.52, 95% CI 0.14-1.88, p = 0.462) were not statistically significant. The outcome of heart failure was not consistently reported.

Conclusions: Intravenous hydration likely reduces the incidence of CIN in patients with STEMI undergoing primary PCI. However, for key clinical outcomes such as mortality, heart failure and dialysis the effect estimates were imprecise. Further high quality studies are needed to clarify the appropriate volume of fluid and effects on outcomes.

Keywords: Contrast-induced nephropathy; Intravenous hydration; Primary percutaneous coronary intervention, acute kidney injury, dialysis, mortality; ST-segment elevation-myocardial infarction.

Fig. 1

Study flow diagram of study selection

Fig. 2

Risk of bias graph: ach risk of bias item presented as percentages across all included studies

Fig. 3

a. Effects of intravenous hydration lowering on risk of contrast-induced nephropathy (Hydration vs. No hydration, using random effects model) The event rate in different study arms is presented alongside the computed risk ratio (95% confidence interval [CI] (lower and upper limit) with p value. Forest plot shows effect size (solid squares) with 95% CI (black line through the solid squares), in terms of risk ratio for individual studies and pooled risk ratio (open diamonds) for random effects model at the bottom. Studies favouring reduction of risk with isotonic hydration are on the left of the centre line, and studies favouring control arm are on right of the centre line. b. Effects of intravenous saline hydration lowering on risk of contrast-induced nephropathy (Saline vs. No hydration) The event rate in different study arms is presented alongside the computed risk ratio (95% confidence interval [CI] (lower and upper limit) with p value. Forest plot shows effect size (solid squares) with 95% CI (black line through the solid squares), in terms of risk ratio for individual studies and pooled risk ratio (open diamonds) for random effects model at the bottom. Studies favouring reduction of risk with normal saline hydration are on the left of the centre line, and studies favouring control arm are on right of the centre line

Fig. 4

Effects of intravenous hydration lowering on risk of in-hospital requirement for dialysis (Hydration vs. No hydration)

Fig. 5

Effects of intravenous hydration lowering on risk of in-hospital all-cause mortality (Hydration vs. No hydration)