Blood transfusion and the risk of acute kidney injury after transcatheter aortic valve implantation.

BACKGROUND: Blood transfusion is associated with acute kidney injury (AKI) after transcatheter aortic valve implantation (TAVI). We sought to elucidate in more detail the relation between blood transfusion and AKI and its effects on short- and long-term mortality. METHODS AND RESULTS: Nine hundred ninety-five patients with aortic stenosis underwent TAVI with the Medtronic CoreValve or the Edwards Valve in 7 centers. AKI was defined by the Valve Academic Research Consortium (absolute increase in serum creatinine ≥0.3 mg/dL [≥26.4 µmol/L] or ≥50% increase ≤72 hours). Logistic and Cox regression was used for predictor and survival analysis. AKI occurred in 20.7% (n=206). The number of units of blood transfusion ≤24 hours was the strongest predictor of AKI (≥5 units, OR, 4.81 [1.45-15.95], 3-4 units, OR, 3.05 [1.24-7.53], 1-2 units, OR, 1.47 [0.98-2.22]) followed by peripheral vascular disease (OR, 1.48 [1.05-2.10]), history of heart failure (OR, 1.43 [1.01-2.03]), leucocyte count ≤72 hours after TAVI (OR, 1.05 [1.02-1.09]) and European System for Cardiac Operative Risk Evaluation (EuroSCORE; OR, 1.02 [1.00-1.03]). Potential triggers of blood transfusion such as baseline anemia, bleeding-vascular complications, and perioperative blood loss were not identified as predictors. AKI and life-threatening bleeding were independent predictors of 30-day mortality (OR, 3.15 [1.56-6.38], OR, 6.65 [2.28-19.44], respectively), whereas transfusion (≥3 units), baseline anemia, and AKI predicted mortality beyond 30 days. CONCLUSIONS: AKI occurred in 21% of the patients after TAVI. The number of blood transfusions but not the indication of transfusion predicted AKI. AKI was a predictor of both short- and long-term mortality, whereas blood transfusion predicted long-term mortality. These findings indicate that outcome of TAVI may be improved by more restrictive use of blood transfusions.

Impact of baseline renal function on mortality after percutaneous coronary intervention with sirolimus-eluting stents or bare metal stents.

Renal impairment is an important predictor of mortality after percutaneous coronary intervention and may increase the restenosis rate. However, the relation between restenosis and the risk of death in patients who have renal impairment remains unclear. We evaluated the incidences of repeat revascularization and mortality in patients who had renal impairment and those who did not and who received sirolimus-eluting stents or bare stents. A total of 1,080 consecutive patients treated for 1 year had available data to calculate baseline creatinine clearance. Patients received bare stents (first 6 months, n = 543) or sirolimus-eluting stents (last 6 months, n = 537) and were grouped according to the presence or absence of renal impairment (creatinine clearance <60 ml/min). Patients who had renal impairment had a higher mortality rate at 1 year (7.6% vs 2.5%, hazard ratio 3.14, 95% confidence interval 1.68 to 5.88, p <0.01), with no differences in mortality between patients who received bare stents and those who received sirolimus-eluting stents (hazard ratio 0.91, 95% confidence interval 0.49 to 1.68, p = 0.8). The incidence of target vessel revascularization decreased significantly in patients who were treated with sirolimus-eluting stents and did not have renal impairment (hazard ratio 0.59, 95% confidence interval 0.39 to 0.90, p = 0.01) and in those who had decreased renal function (hazard ratio 0.37, 95% confidence interval 0.15 to 0.90, p = 0.03). Thus, sirolimus-eluting stents compared with conventional stents decreased clinical restenosis in patients who had renal impairment. However, this benefit was not paralleled by a decrease in the risk of death in this population. It seems unlikely that restenosis could be a contributing factor that influenced the increased mortality of patients who had impaired renal function.

Comparison of late luminal loss response pattern after sirolimus-eluting stent implantation or conventional stenting.

BACKGROUND: We investigated the pattern of late luminal loss after sirolimus-eluting or bare stent implantation. METHODS AND RESULTS: The study population comprised 238 patients treated with sirolimus-eluting stents and 526 patients treated with conventional stents. The distribution of late loss of sirolimus stents was largely skewed to the right and differed from the distribution for bare stents. When divided according to the presence of binary restenosis (diameter stenosis >50%), restenotic lesions in the bare stent group (26.0%) had a late loss of 1.40+/-0.64 mm and in the sirolimus group (7.9%) of 1.16+/-0.76 mm. Nonrestenotic lesions in the bare stent group had a late loss of 0.58+/-0.44 mm, whereas the late loss of nonrestenotic lesions in the sirolimus group remained close to zero (-0.05+/-0.33 mm). Differences between poststenting and follow-up measurements in the sirolimus group (late loss) resembled variations observed in repeated angiographic measurements, as assessed from a random sample of 30 segments measured repeatedly. After multivariate adjustment, stent type did not influence the degree of late loss in restenotic lesions. However, nonrestenotic bare stents had a significantly larger estimated luminal loss (0.58 mm; 95% CI, 0.52 to 0.65) than sirolimus-eluting stents, for which the predicted late loss was almost 0 (-0.04 mm; 95% CI, -0.10 to 0.02). CONCLUSIONS: The pattern of late loss after sirolimus-eluting stent implantation follows a peculiar behavior, different from lesions treated with conventional stents. Whether this is explained by an unusual statistical distribution or a biological all-or-none response of restenosis after sirolimus-eluting stenting remains to be investigated.

Fate of Side Branches After Coronary Arterial Sirolimus-Eluting Stent Implantation

The sirolimus-eluting stent (SES) is emerging as a potential solution for the prevention of restenosis. Although the outcome of side branches after stenting with an uncoated metal stent (UMS) has been reported, the fateof side branches after SES implantation is unknown.Furthermore, the absence of spontaneous recanalizationof occluded side branches following intracoronarybrachytherapy has been previously described and hasbeen related to a delayed healing process. We assessedthe procedural and 6-month follow-up angiograms of238 patients enrolled in the RAVEL study, a double-blindcontrolled trial of the SES versus the UMS. Any sidebranch seen on the preprocedure angiogram and subsequentlycovered by the stent was evaluated. The side branch Thrombolysis In Myocardial Infarction (TIMI) flow grade was assessed at baseline and at follow-up by 2 observers. One hundred twenty-eight patients with >1 side branches were identified (63 patients in the SES group with 118 side branches, 65 patients in the UMS group with 124 side branches). Side branch occlusion occurred after stenting in 12 branches (10%) in the SES group and in 9 branches (7%) in the UMS group (p NS). Of these occluded branches, spontaneous recanalization was observed in 11 branches (92%) in the SES group and in 6 branches (67%) in the UMS group at follow-up angiography (p NS). Thus, the fate of side branches after SES implantation is favorable and at least as good as after UMS implantation.