CRCM Journal

Introduction

Aortic stenosis (AS) is the most common valvular heart disease [1,2]. As atherosclerosis and AS share similar pathophysiology and risk factors, concomitant coronary artery disease (CAD) is highly prevalent among patients with severe AS and is associated with poorer outcomes [3]. CAD has been reported in more than 50% of AS patients undergoing both surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) [4,5].

The comparative efficacy of TAVR and SAVR has been evaluated in large randomized trials, but patients with CAD requiring coronary revascularization were excluded from the majority of trials [6-8].

Subjects and Methods

The purpose of this study was to compare outcomes of TAVR + percutaneous coronary artery intervention (PCI) compared with SAVR + coronary artery bypass grafting (CABG) procedures in adult patients with concomitant severe AS and CAD.

A retrospective study involved 200 patients with significant AS, requiring prosthetic valve implantation, admitted to our hospital between January 2017 – December 2019. All of these patients also had CAD with significant stenoses of coronary arteries, requiring interventional or surgical treatment. Patients were divided into two groups – the first group was patients, who underwent TAVR + PCI within four to five weeks between procedures. The second group consisted of patients, who underwent SAVR + CABG simultaneously.

The research was approved by the Bioethics committee of our university. Data collected were epidemiological data, comorbidities, echocardiography parameters before the aortic valve replacement and within a month after the replacement, the type of prosthesis, early complications of the procedure and mortality rate for four years.

Data was analysed using IBM SPSS Statistics v26.0. Data was assessed using Smirnov-Kolmogorov test. Non-parametrical quantitative data was presented as median with minimal and maximal values. Parametrical quantitative data was presented as mean with standart deviation. Non-parametrical comparative data was assessed using Mann-Whitney test. Parametrical comparative data was assessed using Student T-test. Numeric data was presented as numbers and percentages. Groups were compared using Wilcoxon signed-rank test. Categorical variables were expressed as absolute numbers (percentages) and compared using the χ2 test. A p value <0,05 was concerned as statistically significant data.

Results

Two hundred patients were included. Of them, one hundred patients underwent TAVR + PCI and one hundred patients underwent SAVR + CABG. The baseline characteristics of the patients are presented in (Table 1). Patients in TAVR + PCI group were older, had significantly more comorbidities (prior myocardial infarction, chronic kidney disease, atrial fibrillation). Also, there was a significantly higher number of interventions in TAVR + PCI group (permanent pacemaker implantation, prior PCI and CABG) performed prior to TAVR.

Table 1: Baseline clinical characteristics of study cohort.

SAVR + CABG group had significantly more patients with diabetes mellitus and better renal function. They were more likely to be in New York Heart Association (NYHA) class III or IV and had lower values of hemoglobin, but these differences were not statistically significant.

The early outcomes of the TAVR + PCI and SAVR + CABG groups were assessed and compared in the period of 30 days after the procedures. The results are shown in (Table 2).

Table 2: The 30-day outcomes.

The 30-day mortality rate was higher in SAVR + CABG group, but this difference was not statistically significant. Complications as stroke, aortic dissection, myocardial infarction, third-degree atrioventricular block, infectious endocarditis, cardiac tamponade, sepsis were compared, but there were no significant differences between the groups. Complications as new onset atrial fibrillation (NOAF), acute kidney injury (AKI) and red blood cells (RBC) transfusions were significantly more prevalent in SAVR + CABG group.

The baseline echocardiographic characteristics between TAVR+PCI and SAVR+CABG patients are shown in (Table 3). Before valve implantation TAVR+PCI patients had a higher peak aortic valve gradient and a greater frequency of moderate or severe aortic regurgitation. Also, in TAVR + PCI group was significantly greater frequency of moderate and higher mitral and tricuspid regurgitation.

Table 3: Baseline echocardiographic results: aortic valve hemodynamics.

Left ventricular ejection fraction (LVEF), aortic valve peak gradient and mean pulmonary artery pressure (mPAP) were compared in groups before and after the surgery. The results are shown in (Figures 1-3).  Echocardiography parameters assessment after the surgery showed statistically significant differences in changes before and after the intervention between groups in mean pulmonary artery pressure (p<0.001) (Figure 2). Patients with an implanted transcatheter heart valve had a significantly lower peak aortic gradient at 30 days compared to patients treated with SAVR (15.56 ± 0.66 mmHg vs 25.77 ± 1.39 mmHg, accordingly, p=0.002). The percentage of ≥ moderate paravalvular aortic, total aortic regurgitation was significantly higher in TAVR+PCI group (p <0.001) (Table 4).

Figure 1: Differences in aortic valve peak gradient between groups before and after the intervention (p = 0.002). Abbreviations: CABG – coronary artery bypass grafting, PCI – percutaneous coronary intervention, SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

Figure 2: Differences in mean pulmonary artery pressure between groups after intervention (p<0.001). Abbreviations: CABG – coronary artery bypass grafting; PCI – percutaneous coronary intervention; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

Figure 3: Differences in left ventricular ejection fraction between groups after intervention (p=0.002). Abbreviations: CABG – coronary artery bypass grafting, LVEF – left ventricular ejection fraction; PCI – percutaneous coronary intervention; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

Table 4: Echocardiographic results after aortic valve replacement

Also, there was a difference in change of LVEF – it improved from mean LVEF 46.98 ± 10.85 to 47.41±10.25 in TAVI+PCI group and from 46.30 ± 12.04 to 47.88 ± 9.85 in SAVR + CABG group (Figure 3) (p=0.002). There also were statistically significant differences between groups in the duration of hospitalization. Patients included to SAVR + CABG group had longer hospitalization than in TAVR + PCI group (p=0.002) (Figure 4).

Figure 4. Differences in duration of hospitalization between groups after intervention. Abbreviations: CABG – coronary artery bypass grafting; PCI – percutaneous coronary intervention; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

To evaluate long term outcomes – mortality rate yearly for four years was assessed. There was a tendency – short term mortality rate (at 30-days follow-up and at one year follow – up) was higher in SAVR + CABG group, long term (at 2 years, 3 years and four years follow – up) mortality rate was higher in TAVR + PCI group, but these differences were not significant (Figure 5).

Figure 5: Mortality rate between groups in 30-day period and at follow-up for four years. Abbreviations: CABG – coronary artery bypass grafting; PCI – percutaneous coronary intervention; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.