Prevalence and prognostic impact of comorbidities in patients with severe aortic valve stenosis

Preoperative heart failure worsens outcome after aortic valve replacement irrespective of left ventricular ejection fraction

BACKGROUND

Left ventricular ejection fraction (LVEF) affects outcome of valve replacement (AVR) in aortic stenosis (AS). The study aim was to investigate the prognostic importance of concomitant cardiovascular disease in relation to preoperative LVEF.

METHODS AND RESULTS

All adult patients undergoing AVR due to AS 2008-2014 in a national register for heart diseases were included. All-cause mortality and hospitalization for heart failure during follow-up after AVR, stratified by preserved or reduced LVEF (=50%), was derived from national patient registers and analyzed by Cox regression.During the study period 10,406 patients, median age 73 years, a median follow-up of 35 months were identified. Preserved LVEF was present in 7,512 (72.2%). Among them 647 (8.6%) had a history of heart failure (HF) and 1,099 (14.6%) atrial fibrillation (AF) before intervention. Preoperative HF was associated with higher mortality irrespective of preserved or reduced LVEF: Hazard Ratio (HR) 1.64 (95% C.I. 1.35 -1.99) and 1.58 (95% C.I. 1.30 -1.92). Prior AF was associated with a higher risk of mortality in patients with preserved but not in those with reduced LVEF: HR 1.62 (95% C.I. 1.36 -1.92) and 1.05 (95% C.I. 0.86 -1.28). Irrespective of LVEF preoperative HF and AF were associated with an increased risk of postoperative heart failure hospitalization.

CONCLUSION

In patients planned for AVR, a history of HF or AF, irrespective of LVEF, worsens the postoperative prognosis. HF and AF can be seen as markers of myocardial fibrosis not necessarily discovered by LVEF and the merely use of it, besides symptoms, for timing of AVR seems suboptimal.

Effect of correction of anemia on echocardiographic and clinical parameters in patients with aortic stenosis involving a three-cuspid aortic valve and normal left ventricular ejection fraction

The objective of the study is to investigate the impact of anemia (defined as hemoglobin concentration of <12 g/dl in women and 13 g/dl in men) on prognosis and to study the effect of recovery from anemia on echocardiographic and clinical parameters in patients with aortic stenosis (AS). This was a prospective study in 315 patients with moderate or severe AS. Patients with anemia received oral iron (ferrous sulfate with mucoproteose, 160 mg iron/day) and erythropoietin, if needed, or intravenous iron, if necessary. The following tests were performed before and after normalization of hemoglobin values: echocardiogram, 6-minute walk test, N-terminal B-type natriuretic peptide, and measures of depression, cognitive impairment, and dependence. Patient mean age was 74 years (SD 9). Mean follow-up was 25 months (SD 8). Anemia prevalence in the overall group was 22% (n = 70). Patients who are anemic had a higher rate of complications at follow-up (mortality, hospital admission, or need for valve procedure; 80% vs 62%, p = 0.009). In total, 89% of patients recovered from anemia, with a mean time to recovery of 4.6 weeks (SD 1.4). Improvements were observed on echocardiographic parameters of peak velocity (4.1 to 3.7 m/s, p = 0.02) and mean gradient (44 to 35 mm Hg, p = 0.02). Performance on the 6-minute walk test improved from 235 to 303 m (p <0.001). Median N-terminal B-type natriuretic peptide value decreased from 612 to 189 pg/dl (p <0.001). In conclusion, patients with AS and anemia have a worse prognosis than those without anemia. Resolution of anemia is associated with improvements in echocardiographic parameters and functional status, suggesting that treatment of iron deficiency is a relevant option in the management of patients with AS, particularly in nonoperable cases.

Can postoperative mean transprosthetic pressure gradient predict survival after aortic valve replacement?

Background

In this study, we sought to determine the effect of the mean transprosthetic pressure gradient (TPG), measured at 6 weeks after aortic valve replacement (AVR) or AVR with coronary artery bypass grafting (CABG) on late all-cause mortality.

Methods

Between January 1998 and March 2012, 2,276 patients (mean age 68 ± 11 years) underwent TPG analysis at 6 weeks after AVR (n = 1,318) or AVR with CABG (n = 958) at a single institution. Mean TPG was 11.6 ± 7.8 mmHg and median TPG 11 mmHg. Based on the TPG, the patients were split into three groups: patients with a low TPG (<10 mmHg), patients with a medium TPG (10–19 mmHg) and patients with a high TPG (≥20 mmHg). Cox proportional-hazard regression analysis was used to determine univariate predictors and multivariate independent predictors of late mortality.

Results

Overall survival for the entire group at 1, 3, 5, and 10 years was 97, 93, 87 and 67 %, respectively. There was no significant difference in long-term survival between patients with a low, medium or high TPG (p = 0.258). Independent predictors of late mortality included age, diabetes, peripheral vascular disease, renal dysfunction, chronic obstructive pulmonary disease, a history of a cerebrovascular accident and cardiopulmonary bypass time. Prosthesis–patient mismatch (PPM), severe PPM and TPG measured at 6 weeks postoperatively were not significantly associated with late mortality.

Conclusions

TPG measured at 6 weeks after AVR or AVR with CABG is not an independent predictor of all-cause late mortality and there is no significant difference in long-term survival between patients with a low, medium or high TPG.

Preoperative hemoglobin level as a predictor of mortality after aortic valve replacement

OBJECTIVES

The predictive value of preoperative hemoglobin (HB) level on the outcome of patients undergoing valve surgery is not well established. This study evaluated the predictive value of preoperative HB level on survival after aortic valve replacement (AVR).

DESIGN

This was a retrospective analysis of prospectively collected data.

SETTING

A single-center study performed in an educational hospital.

PARTICIPANTS

All consecutive patients (n = 1,808) who underwent AVR between January 1998 and December 2010.

INTERVENTIONS AVR MEASUREMENTS AND MAIN RESULTS

Patients were classified into 4 groups according to the preoperative HB level: very low (HB of <12 g/dL in men and <11 g/dL in women), low (HB of 12-13 g/dL in men and 11-12 g/dL in women), normal (HB of 13-14.5 g/dL in men and 12-13.5 g/dL in women), and high normal (HB of ≥14.5 g/dL in men and ≥13.5 g/dL in women). The mean follow-up duration was 5.58±3.5 years, and the median follow-up duration was 5.38 years. The mean preoperative HB was 14±1.6 g/dL for men and 13.0±2.1 g/dL for women. Early mortality (≤30 days) was 6.1% in the very-low-HB group, 5.4% in the low-HB group, 3.2% in the normal HB group, and 2.3% in the high-normal-HB group (p = 0.37). Late mortality (>30 days) was 26.1% in the very-low-HB group, 23.7% in the low-HB group, 17.1% in the normal-HB group, and 12.6% in the high-normal-HB group (p<0.0001). The multivariate logistic regression model did not identify low HB as an independent predictor for early mortality. Cox regression multivariate analysis revealed both HB level, as a continuous variable, (p = 0.006), and very-low-HB level (p<0.0001), as independent predictors of late mortality. Cox regression analyses, corrected for confounders, demonstrated that low-HB level is an independent predictor for higher overall mortality (hazard ratio = 2.00, CI 1.41-2.85, p≤0.0001).

CONCLUSIONS

In patients undergoing AVR, preoperative low-HB level is an independent risk factor for late mortality, but not for early mortality.

Left atrial diameter, aortic mean gradient, and hemoglobin for risk stratification in patients undergoing transcatheter aortic valve implantation

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is an alternative treatment of severe symptomatic aortic stenosis (AS) in patients with high operative risk. In spite of favorable entire results, long-term mortality of patients is high.

HYPOTHESIS

The present study aims to identify independent preprocedural risk factors to improve risk stratification in these highly selected patients.

METHODS

This prospective study included 202 consecutive patients with severe symptomatic AS and high operative risk (mean logistic European System for Cardiac Operative Risk Evaluation, 22±17%; mean age, 79±6 years; 107 female). Preprocedural comprehensive examinations were performed (laboratory, electrocardiography, echocardiography, cardiac catheterization). All patients received transfemoral or transaxillary TAVI with a CoreValve prosthesis (Medtronic, Minneapolis, MN).

RESULTS

During a follow-up of 535±333 days, 56 patients (28%) reached the primary study end point (all-cause mortality). Independent predictors of long-term mortality were as follows: hemoglobin<12.5 g/dL (hazard risk [HR], 3.62; 95% confidence interval [CI], 2.025-6.468; P<0.001), aortic mean gradient≤41 mm Hg (HR, 2.16; 95% CI, 1.272-3.655; P=0.004), and left atrial diameter>42 mm (HR, 3.09; 95% CI, 1.588-6.019; P=0.001). Our risk-stratification model based on these independent predictors separated patients into 4 groups with high (74%), intermediate (37%), low (18%), and very low (3%) all-cause mortality.

CONCLUSIONS

In patients undergoing TAVI, preprocedural assessment of hemoglobin, aortic mean gradient, and left atrial diameter provides independent prognostic information and therefore contributes to improved risk stratification in TAVI.

The bicuspid aortic valve and its relation to aortic dilation

BACKGROUND

A bicuspid aortic valve (BAV) is a common congenital heart disease, which affects 1-2% of the population. However, the relationship between BAVs and aortic dilation has not been sufficiently elucidated.

METHODS

A total of 241 BAV patients who were referred to this hospital for cardiac surgery over a 4.75-year period were included in this study. In addition to the clinical characteristics of the included patients, the morphological features of the aortic valve and aorta, the length of the left main coronary artery, and the laboratory findings (the coagulation and hematological parameters as well as the total cholesterol concentration) were determined and compared with those of the tricuspid aortic valve (TAV) patients.

RESULTS

The BAV patients were younger than the TAV patients for a valve surgery in the last 3 months of the study period. The BAV patients were predominantly male. Most of the BAVs that were surgically treated were stenotic, regurgitant, or combined, and only 19 (7.88%) were normally functioning valves. According to echocardiography or operative records, 148 (78.31%) were type A, 31 (16.40%) were type B, and 10 (5.29%) were type C. The left main coronary artery was much shorter in the BAV patients than it was in the TAV patients. There was no significant difference between BAV and TAV patients in the total cholesterol concentrations; whereas differences were noted between patients receiving lipid-lowering therapy and those not receiving lipid-lowering therapy. The dimensions of the aortic root, sinotubular junction, and ascending aorta were beyond normal limits, while they were significantly smaller in the BAV patients than in the TAV patients. They were also much smaller in patients receiving statin therapy than those not receiving statin therapy in both groups. Moreover, the aortic dilation in the BAV group was found to be significantly associated with patient age.

CONCLUSIONS

The BAV patients developed aortic wall and aortic valve disorders at a younger age than the TAV patients and were predominantly male. Aortic dilation was observed in the aortic root, sinotubular junction, and ascending aortic segments in both the BAV and TAV patients undergoing surgical aortic valve replacement, although the BAV patients had a smaller degree of dilation than the TAV patients, and dilation was also significantly age-related in this group. The shorter left main coronary artery that the BAV patients possess may contribute to the progressive course of aortic dilation that these patients experience. Statin therapy did not affect the aortic annulus in either group, but did decrease the dimensions of the aortic root, sinotubular junction and ascending aorta. In general, statin therapy had a better effect on the aortas of the TAV patients than it did on those of the BAV patients.

Eight-year follow-up after prospectively randomized implantation of different mechanical aortic valves

OBJECTIVE

The aim of this prospectively randomized study was to evaluate the hemodynamic and functional outcomes after aortic valve replacement with three different bileaflet mechanical valves.

METHODS

From March 1996 to August 1998, 300 consecutive patients were randomly assigned to receive ATS (n = 100), Carbomedics (n = 100), or St Jude Medical Hemodynamic Plus (n = 100) mechanical aortic valve replacement. There were no significant differences regarding patient age (61 +/- 8 years), gender, NYHA, aortic valve pathology, ventricular morphology, ejection fraction and requirement for additional procedures at implant. Mean follow-up extends to 95 +/- 21 months at a total of 2,891 patients years and is in 95.3% complete.

RESULTS

Implanted valve sizes were comparable at 24 +/- 2 mm (ATS), 23.7 +/- 1.6 mm (CM), and 23.6 +/- 1.9 mm (SJMHP) (NS). Follow-up results were: transvalvular flow velocities 2.3/2.3/2.2 m/s, ejection fraction 64/59/63%, trivial transvalvular incompetence 3/3/2; paravalvular leak 2/3/2; freedom of reoperation 100/99/99%, NYHA functional status 1.5/1.8/1.6, overall survival 86.4/82.8/80.6%, freedom from thrombembolic events 100/96/98%, freedom from hemorrhage 100/100/99%, freedom from all valve related events was 100/96/98%; respectively (NS). There were no episodes of endocarditis. Ninety-four percent of the patients were satisfied with the procedure enjoying an enhanced daily life activity.

CONCLUSIONS

There are no clinically relevant differences among the tested bileaflet aortic valves. Regardless of valve type, there was a rather low complication rate in this relatively young population. All three bileaflet prostheses are well suited for aortic valve replacement.