Improvement of renal function after transcatheter aortic valve replacement in patients with chronic kidney disease

Background

Chronic kidney disease is commonly found in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) and has marked impact in their prognosis. It has been shown however that TAVR may improve renal function by alleviating the hemodynamic barrier imposed by AS. Nevertheless, the predictors of and clinical consequences of renal function improvement are not well established.

Our aim was to assess the predictors of improvement of renal function after TAVR.

Methods

The present work is an analysis of the Brazilian Registry of TAVR, a national non-randomized prospective study with 22 Brazilian centers. Patients with baseline renal dysfunction (estimated glomerular filtration rate [eGFR] < 60mL/min/1.73m²) were stratified according to renal function after TAVR: increase >10% in eGFR were classified as TAVR induced renal function improvement (TIRFI); decrease > 10% in eGFR were classified as acute kidney injury (AKI) and stable renal function (neither criteria).

Results

A total of 819 consecutive patients with symptomatic severe AS were included. Of these, baseline renal dysfunction (estimated glomerular filtration rate [eGFR] < 60mL/min/1.73m²) was present in 577 (70%) patients. Considering variance in renal function between baseline and at discharge after TAVR procedure, TIRFI was seen in 197 (34.1%) patients, AKI in 203 (35.2%), and stable renal function in 177 (30.7%).

The independent predictors of TIRFI were: absence of coronary artery disease (OR: 0.69; 95% CI 0.48–0.98; P = 0.039) and lower baseline eGFR (OR: 0.98; 95% CI 0.97–1.00; P = 0.039). There was no significant difference in 30-day and 1-year all-cause mortality between patients with stable renal function or TIRFI. Nonetheless, individuals that had AKI after TAVR presented higher mortality compared with TIRFI and stable renal function groups (29.3% vs. 15.4% vs. 9.5%, respectively; p < 0.001).

Conclusions

TIRFI was frequently found among baseline impaired renal function individuals but was not associated with improved 1-year outcomes.

Late clinical outcomes of myocardial hybrid revascularization versus coronary artery bypass grafting for complex triple-vessel disease: Long-term follow-up of the randomized MERGING clinical trial

OBJECTIVES

This article aimed to compare the outcomes after hybrid revascularization with conventional coronary artery bypass grafting (CABG) surgery.

BACKGROUND

The concept of hybrid coronary revascularization combines the advantages of CABG and percutaneous coronary intervention to improve the treatment of patients with complex multivessel disease.

METHODS

The Myocardial hybrid revascularization versus coronary artERy bypass GraftING for complex triple-vessel disease-MERGING study is a pilot randomized trial that allocated 60 patients with complex triple-vessel disease to treatment with hybrid revascularization or conventional CABG (2:1 ratio). The primary outcome was the composite of all-cause death, myocardial infarction, stroke, or unplanned repeat revascularization at 2 years.

RESULTS

Clinical and anatomical characteristics were similar between groups. After a mean follow-up of 802 ± 500 days, the primary endpoint rate was 19.3% in the hybrid arm and 5.9% in the CABG arm (p = NS). The incidence of unplanned revascularization increased over time in both groups, reaching 14.5 versus 5.9% in the hybrid and in the CABG groups, respectively (p = .4). Of note, in the hybrid group, there were no reinterventions driven by the occurrence of stent restenosis.

CONCLUSIONS

Hybrid myocardial was feasible but associated with increasing rates of major adverse cardiovascular events during 2 years of clinical follow-up, while the control group treated with conventional surgery presented with low rates of complications during the same period. In conclusion, before more definitive data arise, hybrid revascularization should be applied with careful attention in practice, following a selective case-by-case indication.

Impact of Acute Kidney Injury on Short- and Long-term Outcomes After Transcatheter Aortic Valve Implantation

INTRODUCTION AND OBJECTIVES

Acute kidney injury (AKI) is frequently observed after transcatheter aortic valve implantation (TAVI) and is associated with higher mortality. However, the impact of AKI on long-term outcomes remains controversial. Therefore, we sought to evaluate the impact of AKI on short- and long-term outcomes following TAVI using the Valve Academic Research Consortium 2 criteria.

METHODS

Consecutive patients (n = 794) with severe aortic stenosis who underwent TAVI were included in a multicenter Brazilian registry. Logistic regression analysis was used to identify predictors of AKI. Four-year outcomes were determined as Kaplan-Meier survival curves, and an adjusted landmark analysis was used to test the impact of AKI on mortality among survivors at 12 months.

RESULTS

The incidence of AKI after TAVI was 18%. Independent predictors of AKI were age, diabetes mellitus, major or life-threatening bleeding and valve malpositioning. Acute kidney injury was independently associated with higher risk of all-cause death (adjusted HR, 2.8; 95%CI, 2.0-3.9; P < .001) and cardiovascular mortality (adjusted HR, 2.9; 95%CI, 1.9-4.4; P < .001) over the entire follow-up period. However, when considering only survivors at 12 months, there was no difference in both clinical endpoints (adjusted HR, 1.2; 95%CI, 0.5-2.4; P = .71, and HR, 0.7; 95%CI, 0.2-2.1; P = .57, respectively).

CONCLUSIONS

Acute kidney injury is a frequent complication after TAVI. Older age, diabetes, major or life-threatening bleeding, and valve malpositioning were independent predictors of AKI. Acute kidney injury is associated with worse short- and long-term outcomes. However, the major impact of AKI on mortality is limited to the first year after TAVI.

Allogeneic pASC transplantation in humanized pigs attenuates cardiac remodeling post-myocardial infarction

Cell therapy repair strategies using adult mesenchymal stromal cells have shown promising evidence to prevent cardiac deterioration in rodents even in the absence of robust differentiation of the cells into cardiomyocytes. We tested whether increasing doses of porcine adipose-tissue derived mesenchymal stem cells (pASCs) increase cardiac tissue perfusion in pigs post-myocardial infarction (MI) receiving angiotensin-converting-enzyme inhibitor (ACE inhibitors) and Beta-blockers similarly to patients. Female pigs were subjected to MI induction by sponge permanent occlusion of left circumflex coronary artery (LCx) generating approximately 10% of injured LV area with minimum hemodynamic impact. We assessed tissue perfusion by real time myocardial perfusion echocardiography (RTMPE) using commercial microbubbles before and following pASCs treatment. Four weeks after the occlusion of the left circumflex artery, we transplanted placebo or pASCs (1, 2 and 4x10⁶ cells/Kg BW) into the myocardium. The highest dose of pASCs increased myocardial vessel number and blood flow in the border (56% and 3.7-fold, respectively) and in the remote area (54% and 3.9-fold, respectively) while the non-perfused scar area decreased (up to 38%). We also found an increase of immature collagen fibers, although the increase in total tissue collagen and types I and III was similar in all groups. Our results provide evidence that pASCs-induced stimulation of tissue perfusion and accumulation of immature collagen fibers attenuates adverse remodeling post-MI beyond the normal beneficial effects associated with ACE inhibition and beta-blockade.