Morbidity outcomes after surgical aortic valve replacement

Comparison of Contemporary Treatment Strategies in Patients With Cardiogenic Shock Due to Severe Aortic Stenosis

BACKGROUND

The aims of this study were to understand the incidence and outcomes of patients with cardiogenic shock (CS) due to severe aortic stenosis (AS), and the impact of conventional treatment strategies in this population.

METHODS AND RESULTS

All patients admitted to the Cleveland Clinic cardiac intensive care unit between January 1, 2010 and December 31, 2021 with CS were retrospectively identified and categorized into those with CS in the setting of severe AS versus CS without AS. The impact of various treatment strategies on mortality was further assessed. We identified 2754 patients with CS during the study period, of whom 216 patients (8%) had CS in the setting of severe AS. Medical management was associated with the highest 30-day mortality when compared with either balloon aortic valve replacement or aortic valve replacement (surgical or transcatheter aortic valve replacement) (hazard ratio, 3.69 [95% CI, 2.04-6.66]; P<0.0001). Among patients who received transcatheter therapy, 30-day mortality was significantly higher in patients who received balloon aortic valvuloplasty versus transcatheter aortic valve replacement (26% versus 4%, P=0.02). Both surgical and transcatheter aortic valve replacement had considerably lower mortality than medical management and balloon aortic valvuloplasty at 30 days and 1 year (P<0.05 for both comparisons).

CONCLUSIONS

CS due to severe AS is associated with high in-hospital and 30-day mortality, worse compared with those with CS without AS. In suitable patients, urgent surgical aortic valvuloplasty or transcatheter aortic valve replacement is associated with favorable short- and long-term outcomes. Although balloon aortic valvuloplasty may be used to temporize patients with CS in the setting of severe AS, mortality is ≈50% if not followed by definitive aortic valve replacement within 90 days.

Long-Term Outcomes of Mechanical Versus Bioprosthetic Aortic Valve Replacement: A Systematic Review and Meta-Analysis

This study aimed to investigate the safety and efficacy of bioprosthetic (BV) versus mechanical valves (MV) on long-term outcomes in 50- to 70-year-old aortic stenosis (AS) patients. A literature search for articles published until April 2023 yielded 13 eligible studies, with 15,320 patients divided into BV (n = 7,320) and MV (n = 8,000) cohorts. The review was registered prospectively with PROSPERO (CRD42021278777). MV demonstrated a favorable hazard ratio (HR: 1.12, 95% CI: 1.00-1.25, I2 = 60%) and higher survival rates at 5 (OR:1.13, 95% CI: 1.02-1.25, I2 = 42%) and 10 years (OR: 1.13, 95% CI: 1.05-1.23, I2 = 0%). At 15 years, stroke incidence was comparable (OR: 1.12, 95% CI: 0.98-1.27, I2 = 4%). BV showed lower bleeding events (OR: 1.7, 95% CI: 1.18-2.46, I2 = 88%), but MV replacement showed lower reoperation incidence (OR: 0.27, 95% CI: 0.18-0.42, I2 = 85%). MV appears favorable for the long-term approach in AS management compared to BV.

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.

Machine learning-based risk stratification for mortality in patients with severe aortic regurgitation

Aims

The current guidelines recommend aortic valve intervention in patients with severe aortic regurgitation (AR) with the onset of symptoms, left ventricular enlargement, or systolic dysfunction. Recent studies have suggested that we might be missing the window of early intervention in a significant number of patients by following the guidelines.

Methods and results

The overarching goal was to determine if machine learning (ML)-based algorithms could be trained to identify patients at risk for death from AR independent of aortic valve replacement (AVR). Models were trained with five-fold cross-validation on a dataset of 1035 patients, and performance was reported on an independent dataset of 207 patients. Optimal predictive performance was observed with a conditional random survival forest model. A subset of 19/41 variables was selected for inclusion in the final model. Variable selection was performed with 10-fold cross-validation using random survival forest model. The top variables included were age, body surface area, body mass index, diastolic blood pressure, New York Heart Association class, AVR, comorbidities, ejection fraction, end-diastolic volume, and end-systolic dimension, and the relative variable importance averaged across five splits of cross-validation in each repeat were evaluated. The concordance index for predicting survival of the best-performing model was 0.84 at 1 year, 0.86 at 2 years, and 0.87 overall, respectively.

Conclusion

Using common echocardiographic parameters and patient characteristics, we successfully trained multiple ML models to predict survival in patients with severe AR. This technique could be applied to identify high-risk patients who would benefit from early intervention, thereby improving patient outcomes.

Outcomes of 16,436 patients requiring isolated aortic valve surgery: A statewide cohort study

BACKGROUND

Aortic valve surgery (AVS) is the gold standard treatment for symptomatic aortic valve (AV) disease patients. We report the temporal trends in the incidence of patients requiring isolated AVS in an unselected statewide population and their mortality outcomes over 17-years.

METHODS

Patients were identified from the New South Wales, Australia, Admitted-Patient-Data-Collection registry between 1-July-2001 and 31-December-2018. Annual case-volumes and survival outcomes, adjusted for age, sex, referral source, endocarditis, concomitant coronary-artery-bypass-grafting, comorbidities including atrial fibrillation, hypertension and Charlson comorbidity index, were compared across calendar years.

RESULTS

The study cohort comprised 16436 patients who underwent isolated AVS (mean age: 72.2 ± 11.3y; 67.5% males). Annual case-volume increased from 768 to 1048 cases between 2002 and 2017 (r² = 0.82; p < 0.0001). Surgical AV replacement (SAVR) with mechanical valves declined from 271 to 104 (r² = 0.87; p < 0.0001) between 2002 and 2017. In contrast, bioprosthetic SAVR increased from 342 to 729 cases (r² = 0.93; p < 0.0001). The 30-day, 6-month, and 1-year mortality rates improved progressively from 4.39%, 7.72%, and 9.19% in 2002, to 1.89%, 3.49%, and 4.68% by 2017. The adjusted odds ratio for 30-day mortality and hazard ratio for 1-year mortality were 0.33 (95% confidence interval [CI] 0.16-0.69, p < 0.01) and 0.09 (95% CI 0.07-0.12, p < 0.01), respectively. Similar improvements in outcomes were observed after implantation of mechanical or bioprosthetic aortic valves. Heart failure and sepsis were the most common cardiovascular-related and noncardiovascular-related causes death.

CONCLUSION

The volume of AVS has increased progressively over time and has been associated with increased use of bioprosthetic valves and markedly improved 30-day and 1-year survival.

Influence of warfarin on cardiac and cerebrovascular events following bioprosthetic aortic valve replacement: A nationwide cohort study

OBJECTIVE

The need for anticoagulation treatment following bioprosthetic aortic valve replacement remains controversial. We investigated the associations of warfarin treatment with the risks of major adverse cardiac and cerebrovascular events, including mortality, bleeding incidents, and reoperation requirement after bioprosthetic aortic valve replacement surgery.

METHODS

We identified 1086 patients who received first bioprosthetic aortic valve replacement between 2001 and 2010 using Taiwan's National Health Insurance Database. Patients were excluded for prior use of warfarin, warfarin use for >3 months, dual valve procedures, prior valve surgeries, or concomitant surgeries. Enrolled patients were divided into 2 groups according to whether they were warfarin-naïve or received warfarin for <3 months postsurgery. After propensity score matching, 282 patients not receiving warfarin were matched to 282 patients receiving warfarin for <3 months. Patients were followed-up for minimum 36 months.

RESULTS

Patients receiving warfarin were younger and showed less frequent kidney disease than those who did not use warfarin. The warfarin group demonstrated a gross decrease in major adverse cardiac and cerebrovascular events. Patients receiving warfarin for <30 days were at an even lower risk for major adverse cardiac and cerebrovascular events than those treated for ≥30 days. No significant difference in bleeding or reoperation risk was observed between warfarin users and warfarin nonusers. Similar findings remained after propensity-score matching but the benefit of short-term warfarin use diminished in a younger population.

CONCLUSIONS

Short-term use of postoperative warfarin (especially <30 days) following bioprosthetic aortic valve replacement may be associated with a reduction in MACCE compared with nonuse.

Propensity score-matched analysis of patients with severe aortic stenosis undergoing surgical aortic valve replacement

Objective

Severe aortic stenosis (AS) is one of the most serious valve conditions. Patient demography and the aetiology of AS have substantially changed in the past several decades along with a drastic improvement of surgical aortic valve replacement (SAVR) and its associated procedures. Contemporary patients with severe AS have multiple comorbidities and live much longer. We aimed to elucidate the treatment effects of SAVR on long-term outcome in propensity score (PS)-matched and the entire patient populations.

Methods

We retrospectively reviewed 570 patients with severe AS defined as an aortic valve area of 1.0 cm² or less. Systemic differences in 39 baseline characteristics between non-SAVR and SAVR groups were adjusted using PS matching method. The endpoints included all-cause mortality and cardiovascular events that included heart failure, non-fatal stroke, syncope and acute coronary syndrome.

Results

Overall, 55% of the entire population (mean age 78 years; males 41%) were symptomatic. During 3.9 years of the median follow-up, 210 (36%) patients underwent SAVR and 231 (41%) died. Cumulative incidences of mortality and both mortality and cardiovascular events were significantly higher in the non-SAVR group than in the other group (p<0.001, each). Among 101 PS-matched pairs, SAVR correlated with a lower mortality risk (HR 0.35; 95% CI 0.21 to 0.59; p<0.001)) and mortality and cardiovascular events combined (HR 0.62; 95% CI 0.42 to 0.92; p=0.02). However, survival difference between both groups was markedly smaller among asymptomatic patients in the subgroup of matched patients.

Conclusion

Patients with AS undergoing SAVR exhibit a lower incidence of all-cause mortality and major cardiovascular events than those not undergoing surgical interventions, even after the baseline characteristics are balanced by the PS matching. The correlation between SAVR and survival from cardiovascular events is less evident among asymptomatic patients.

Gender differences in incidence and in-hospital outcomes of surgical aortic valve replacement in Spain, 2001–15

Background

we aim to examine trends in the incidence of surgical aortic valve replacement (SAVR) among women and men in Spain from 2001 to 2015; compare in-hospital outcomes for mechanical and bioprosthetic SAVR by gender and; to identify factors associated with in-hospital mortality (IHM) after SAVR.

Methods

We performed a retrospective study using the Spanish National Hospital Discharge Database, 2001–15. We included patients that had SAVR as procedure in their discharge report. Propensity score matching (PSM) was performed to assess the impact of gender on the outcomes of mechanical and bioprosthetic SAVR.

Results

We identified 86 578 patients who underwent SAVR (40% women). Incidence of SVAR was higher in men (incidence rate ratio 1.57; 95%CI 1.55–1.59). In 2001, 73.36% of the men and 71.57% of women received a mechanical prosthesis; these proportions decreased to 43.04% in men and 35.89% in women in 2015, whereas bioprosthetic SAVR increased to 56.96% and 64.11%. After PSM we found that IHM was higher in women than in matched men for mechanical (8.94% vs. 6.79%; P < 0.001) and bioprosthetic (6.51 vs. 5.42%; P = 0.001) SAVR. The mean length of hospital stay was longer (19.54 vs. 18.74 days; P < 0.001) among females than males undergoing mechanical SAVR. Higher IHM after SAVR was associated with older age, comorbidities (except diabetes and atrial fibrillation), concomitant coronary artery bypass graft and emergency room admission.

Conclusions

This nation-wide analysis over 15 years of gender-specific outcomes after SAVR showed that, after PSM women have significantly higher IHM after mechanical and bioprosthetic SAVR than men.

Prevalence and prognostic implication of iron deficiency and anaemia in patients with severe aortic stenosis

Objective

The aim of this study was to evaluate the prevalence and prognostic implication of iron deficiency (ID) and anaemia in patients with severe aortic stenosis (AS).

Methods

In an observational study of consecutive patients referred for aortic valve replacement (AVR), we assessed a wide range of biomarkers of iron status, including the definition of ID commonly applied in patients with chronic heart failure (ferritin <100 µg/L or ferritin 100–299 µg/L with a transferrin saturation <20%). The endpoints were short-term (one-year) and long-term (median 4.7 years, IQR: 3.8–5.5) mortality and major adverse cardiovascular events (MACE) within the first year after inclusion.

Results

464 patients were included in this substudy. 91 patients (20%) received conservative treatment and 373 patients (80%) received AVR. ID was detected in 246 patients (53%). 94 patients (20%) had anaemia. Patients with ID had an overall worse clinical profile than patients without ID. During follow-up, 129 patients (28%) died. Neither ID as defined above, soluble transferrin receptor nor hepcidin were associated with short-term or long-term mortality or MACE independent on treatment allocation. Anaemia was associated with one-year mortality in conservatively treated patients.

Conclusions

ID and anaemia are prevalent in patients with severe AS. In our cohort, ID did not provide independent prognostic information on top of conventional risk factors. More studies are required to determine how to correctly diagnose ID in patients with AS.

Trial registration number

NCT01794832.

Relationship between endotoxin core, staphylococcal and varicella antibody levels and outcome following aortic valve replacement surgery: a prospective observational study

Background

Morbidity and mortality following cardiac valve surgery is high. Immunity is an important contributor to outcome. This study examines the relationship of staphylococcal and endotoxin antibody levels to outcome following cardiac surgery.

Methods

Using enzyme-linked immunosorbent assays (ELISA), we measured pre-operative levels of antibodies to endotoxin core (EndoCAb); 3 common staphylococcal epitopes and varicella on saved serum of 60 adult patients scheduled to undergo elective primary surgical aortic valve replacement (AVR). Primary outcome measure was post-operative length of stay (LOS) in hospital with secondary outcomes being development of infective complications, length of stay on the intensive care unit (ICU) and 30-day mortality. Patients were quartiled according to antibody levels and outcomes compared between the quartile groups using Mann-Whitney tests for length of stay and Fisher's test for development of infection.

Results

Sixty patients (34 M, 26 F) were recruited with mean age 73 years (IQR 66-78), mean body mass index (BMI) 27.7 (IQR 25-31) and EuroSCORE II 1.44 (0.95-1.99). Those patients in the lower quartile for pre-operative antibody level had a longer post-operative stay than the upper quartile. EndoCAb (median IgG level Q1 42.2 MU/ml vs Q4 256 MU/ml) 9 vs 6 days, p = 0.025; alpha-toxin (median IgG level Q1 63 U vs Q4 558 U) 10 vs 7 days, p = 0.034; teichoic acid (median IgG level Q1 14 U vs Q4 419 U) 10 vs 8 days, p = 0.441; staphylococcal enterotoxin A (median IgG level Q1 55 U vs Q4 427 U) 9 vs 7 days, p = 0.865; varicella zoster (median IgG level Q1 1.325 U vs Q4 2.54 U) 8 vs 7 days, p = 1.0; and combined antibody levels 10 vs 6 days, p = 0.017. There were no differences in the number developing post-operative infections for each antibody type. The combined antibody analysis suggested a reduction in proportion of individuals developing infection from the upper vs lower quartile: 0 vs 0.33, p = 0.042.

Conclusions

This study again suggests the inverse relationship between endotoxin core antibody levels and outcome following aortic valve surgery as well as suggesting a similar relationship with antibodies to staphylococcus. There is no such relationship for antibody levels against an organism not providing a peri-operative threat. Understanding this relationship may enable therapeutic manipulation of immune status, re-evaluation of risk and further investigation of the low immune state.

Trial registration

The patients in this study are a sub-group of the RELIEF AS study.ClinicalTrials.gov identifier NCT02174471.

Functional capacity and health-related quality of life outcomes post transcatheter aortic valve replacement: a systematic review and meta-analysis

Background

transcatheter aortic valve replacement (TAVR) provides prognostic benefit for high surgical-risk patients with severe aortic stenosis (AS), yet the impact to patient outcomes is far less understood.

Method

we performed a systematic review and meta-analysis to evaluate functional capacity and health-related quality of life (HRQoL) outcomes for patients up to 12 months post TAVR. A total of 20 eligible publications, comprising randomised-controlled trials, observational studies and a registry study were identified from electronic databases, including MEDLINE, EMBASE, Cochrane Library and others (inception to February 2017).

Results

the total sample was 2,775 with a mean age of 81.8 ± 2.1 years, more than half (52%) were female and high surgical risk 9.6 ± 4.3% mean STS (Society of Thoracic Surgeons risk model). Post TAVR, patients had significant improvement in functional capacity of >40 m in the 6-minute walk test (6MWT) (95% confidence interval (CI) 9.69-73.28) and a clinically meaningful increase in ability to perform daily physical-based tasks (Duke Activity Status Index (DASI), mean difference (MD) increase 5.42 points, 95% CI 3.16-7.68). HRQoL improved consistently following TAVR regardless of measure used. Significant increases occurred in the physical component summary scores (PCS) of the short form (SF) health surveys (MD increase 10.45 (SF36) and 10.14 (SF12) points).

Conclusion

functional capacity and HRQoL improved substantially following TAVR, despite evolving patient selection criteria, thus TAVR continues to provide a directly beneficial option for severe AS patients.