Association Between Type 2 Diabetes and Changes in Myocardial Structure, Contractile Function, Energetics, and Blood Flow Before and After Aortic Valve Replacement in Patients With Severe Aortic Stenosis.

BACKGROUND: Type 2 diabetes (T2D) is associated with an increased risk of left ventricular dysfunction after aortic valve replacement (AVR) in patients with severe aortic stenosis (AS). Persistent impairments in myocardial energetics and myocardial blood flow (MBF) may underpin this observation. Using phosphorus magnetic resonance spectroscopy and cardiovascular magnetic resonance, this study tested the hypothesis that patients with severe AS and T2D (AS-T2D) would have impaired myocardial energetics as reflected by the phosphocreatine to ATP ratio (PCr/ATP) and vasodilator stress MBF compared with patients with AS without T2D (AS-noT2D), and that these differences would persist after AVR. METHODS: Ninety-five patients with severe AS without coronary artery disease awaiting AVR (30 AS-T2D and 65 AS-noT2D) were recruited (mean, 71 years of age [95% CI, 69, 73]; 34 [37%] women). Thirty demographically matched healthy volunteers (HVs) and 30 patients with T2D without AS (T2D controls) were controls. One month before and 6 months after AVR, cardiac PCr/ATP, adenosine stress MBF, global longitudinal strain, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and 6-minute walk distance were assessed in patients with AS. T2D controls underwent identical assessments at baseline and 6-month follow-up. HVs were assessed once and did not undergo 6-minute walk testing. RESULTS: Compared with HVs, patients with AS (AS-T2D and AS-noT2D combined) showed impairment in PCr/ATP (mean [95% CI]; HVs, 2.15 [1.89, 2.34]; AS, 1.66 [1.56, 1.75]; P<0.0001) and vasodilator stress MBF (HVs, 2.11 mL min g [1.89, 2.34]; AS, 1.54 mL min g [1.41, 1.66]; P<0.0001) before AVR. Before AVR, within the AS group, patients with AS-T2D had worse PCr/ATP (AS-noT2D, 1.74 [1.62, 1.86]; AS-T2D, 1.44 [1.32, 1.56]; P=0.002) and vasodilator stress MBF (AS-noT2D, 1.67 mL min g [1.5, 1.84]; AS-T2D, 1.25 mL min g [1.22, 1.38]; P=0.001) compared with patients with AS-noT2D. Before AVR, patients with AS-T2D also had worse PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.66 [1.56, 1.75]; P=0.04) and vasodilator stress MBF (AS-T2D, 1.25 mL min g [1.10, 1.41]; T2D controls, 1.54 mL min g [1.41, 1.66]; P=0.001) compared with T2D controls at baseline. After AVR, PCr/ATP normalized in patients with AS-noT2D, whereas patients with AS-T2D showed no improvements (AS-noT2D, 2.11 [1.79, 2.43]; AS-T2D, 1.30 [1.07, 1.53]; P=0.0006). Vasodilator stress MBF improved in both AS groups after AVR, but this remained lower in patients with AS-T2D (AS-noT2D, 1.80 mL min g [1.59, 2.0]; AS-T2D, 1.48 mL min g [1.29, 1.66]; P=0.03). There were no longer differences in PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.51 [1.34, 1.53]; P=0.12) or vasodilator stress MBF (AS-T2D, 1.48 mL min g [1.29, 1.66]; T2D controls, 1.60 mL min g [1.34, 1.86]; P=0.82) between patients with AS-T2D after AVR and T2D controls at follow-up. Whereas global longitudinal strain, 6-minute walk distance, and NT-proBNP all improved after AVR in patients with AS-noT2D, no improvement in these assessments was observed in patients with AS-T2D. CONCLUSIONS: Among patients with severe AS, those with T2D demonstrate persistent abnormalities in myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function after AVR; AVR effectively normalizes myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function in patients without T2D.

Preoperative Atrial Fibrillation is associated with long-term morTality in patients undergoing suRgical AortiC valvE Replacement.

INTRODUCTION: Atrial fibrillation (AF) is frequent after any cardiac surgery, but evidence suggests it may have no significant impact on survival if sinus rhythm (SR) is effectively restored early after the onset of the arrhythmia. In contrast, management of preoperative AF is often overlooked during or after cardiac surgery despite several proposed protocols. This study sought to evaluate the impact of preoperative AF on mortality in patients undergoing isolated surgical aortic valve replacement (AVR). METHODS: We performed a retrospective, single-center study involving 2628 consecutive patients undergoing elective, primary isolated surgical AVR from 2008 to 2018. A total of 268/2628 patients (10.1%) exhibited AF before surgery. The effect of preoperative AF on mortality was evaluated with univariate and multivariate analyses. RESULTS: Short-term mortality was 0.8% and was not different between preoperative AF and SR cohorts. Preoperative AF was highly predictive of long-term mortality (median follow-up of 4 years [Q1-Q3 2-7]; hazard ratio [HR]: 2.24, 95% confidence interval [CI]: 1.79-2.79, p < .001), and remained strongly and independently predictive after adjustment for other risk factors (HR: 1.54, 95% CI: 1.21-1.96, p < .001) compared with preoperative SR. In propensity score-matched analysis, the adjusted mortality risk was higher in the AF cohort (OR: 1.47, 95% CI: 1.04-1.99, p = .03) compared with the SR cohort. CONCLUSIONS: Preoperative AF was independently predictive of long-term mortality in patients undergoing isolated surgical AVR. It remains to be seen whether concomitant surgery or other preoperative measures to correct AF may impact long-term survival.

Aortic arch surgery for type B aortic dissection: How far should we go? The value of a hybrid approach.

Traditionally, the management of type B aortic dissection has been the domain of the vascular surgeons. Timing and type of intervention still generate debate. We sought to review our early experience with the treatment of this condition based on a hybrid approach following an aortic multi-disciplinary team meeting involving close cooperation between cardiac surgeons, vascular surgeons, interventional radiologists, vascular anesthetists, and cardiac anesthetists. Four patients (age 41-56 years; 3 males; 1 female) with type B aortic dissection underwent aortic arch surgery through a hybrid approach: one elective procedure consisting of ascending aorta and hemi-arch replacement with debranching followed by thoracic endovascular aortic repair (TEVAR); one redo procedure requiring aortic arch replacement with hybrid frozen elephant trunk; two acute presentations (aortic arch replacement and debranching followed by TEVAR; AVR with ascending aorta, arch, and proximal descending thoracic aorta replacement with conventional elephant trunk and debranching). Deep hypothermic circulatory arrest was required in three patients. Despite respiratory complications and slightly prolonged postoperative course, all patients survived without onset of stroke, paraplegia, malperfusion, endoleak, or need for re-exploration. Follow-up remains satisfactory. Different factors may affect outcome following complex aortic procedures. Nevertheless, close cooperation between cardiac surgeons, vascular surgeons, and interventional radiologists may reduce potential for complications and address aspects that may not be completely within the domain of individual specialists.

Prosthesis-Patient Mismatch Increases Early and Late Mortality in Low Risk Aortic Valve Replacement.

The concept of prosthesis-patient mismatch (PPM) has gained much attention since first described 40 years ago. Previous studies have shown conflicting evidence regarding increased early and late morbidity and mortality with PPM after aortic valve replacement (AVR). The aim of this study was to evaluate the effects of PPM on short- and long-term mortality in low-risk patients after isolated AVR. A retrospective, single-center study involving 1707 consecutive patients ≤80 years of age with preserved left ventricular systolic function who underwent elective, primary isolated AVR operations from 2008 to 2018. Patients were stratified into 2 groups according to the presence of PPM (n = 96), defined as effective orifice area index <0.85 cm2/m2 body surface area, and no-PPM (n = 1611). The effect of PPM on mortality was evaluated with univariate and multivariate analyses. 30-day mortality was 0.8% (4.2% in PPM group vs 0.6 in no-PPM group; P = 0.005). PPM occurred more in female gender, obese and older patients. PPM was highly associated with long-term all-cause mortality (median 4 years [Q1-Q3 2-7]; HR: 1.79, 95% CI: 1.27-2.55, P = 0.002), and remained strongly and independently associated after adjustment for other risk factors (HR: 1.60, 95% CI: 1.10-2.34, P = 0.014). In propensity score-matched analysis, the adjusted mortality risk was higher in PPM group (HR: 2.03, 95% CI: 1.22-3.39, P = 0.006) compared to no-PPM group. In a single-centre observational study, PPM increased early mortality and was independently associated with long-term all-cause mortality after low-risk, primary isolated AVR operations. Strategies to avoid PPM should be explored and implemented.

Surgical Repair of Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm in a High-Risk Patient 13 Years after Aortic Root Replacement.

Pseudoaneurysms of the mitral-aortic intervalvular fibrosa are rare complications that can develop after mitral or aortic valve surgery, endocarditis, or Takayasu arteritis. The optimal timing of surgery to avoid potentially life-threatening complications of pseudoaneurysms has not been established, and watchful waiting has been adopted in specific situations. We describe the case of a 50-year-old man in whom a pseudoaneurysm of the mitral-aortic intervalvular fibrosa developed after aortic root replacement with a homograft. After 13 years of watchful waiting, reoperation was deemed necessary because the pseudoaneurysm had grown to 48 mm and the aortic regurgitation caused by the degenerated homograft had become severe. This case highlights the need for increased awareness of mitral-aortic intervalvular fibrosa pseudoaneurysms and their management.