When is concomitant aortic valve replacement indicated in patients with mild to moderate stenosis undergoing coronary revascularization?

Early Surgery versus Watchful Waiting in Patients with Moderate Aortic Stenosis and Left Ventricular Systolic Dysfunction

Background and Objectives

Severe aortic stenosis (AS) with left ventricular systolic dysfunction (LVSD) is a class I indication for aortic valve replacement (AVR) but this recommendation is not well established in those at the stage of moderate AS. We investigate the clinical impact of AVR among patients with moderate AS and LVSD.

Methods

From 2001 to 2017, we consecutively identified patients with moderate AS and LVSD, defined as aortic valve area 1.0–1.5 cm² and left ventricular ejection fraction <50%. The primary outcome was all-cause death. The outcomes were compared between those who underwent early surgical AVR (within 2 years of index echocardiography) at the stage of moderate AS versus those who were followed medically without AVR at the outpatient clinic.

Results

Among 255 patients (70.1±11.3 years, male 62%), 37 patients received early AVR. The early AVR group was younger than the medical observation group (63.1±7.9 vs. 71.3±11.4) with a lower prevalence of hypertension and chronic kidney disease. During a median 1.8-year follow up, 121 patients (47.5%) died, and the early AVR group showed a significantly lower all-cause death rate than the medical observation group (5.03PY vs. 18.80PY, p<0.001). After multivariable Cox-proportional hazard regression adjusting for age, sex, comorbidities, and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of death (hazard ratio, 0.43; 95% confidence interval 0.20–0.91; p=0.028).

Conclusions

In patients with moderate AS and LVSD, AVR reduces the risk of all-cause death. A prospective randomized trial is warranted to confirm our findings.

Management of Less-Than-Severe Aortic Stenosis During Coronary Bypass: A Systematic Review and Meta-Analysis

OBJECTIVE

The management of concomitant mild-to-moderate aortic stenosis (AS) at the time of coronary artery bypass graft (CABG) is controversial. Here we perform a systematic review and meta-analysis of CABG and aortic valve replacement (AVR) versus CABG alone in patients with mild-moderate AS.

METHODS

We searched MEDLINE and EMBASE databases until July 2018 for studies comparing CABG & AVR versus CABG in patients with mild-moderate AS undergoing coronary bypass. Data were extracted by 2 independent investigators. The main outcomes were operative mortality, long-term survival, and reintervention for AS.

RESULTS

There were 6 unmatched retrospective observational studies with 1,172 patients (median follow-up 4.7 [interquartile range: 4.3 to 5.3] years). Patients undergoing CABG & AVR had less severe coronary artery disease. There were no differences in operative mortality (relative risk [RR]: 1.07; 95% CI, 0.59 to 1.94; P = 0.8). CABG & AVR was associated with greater incidence of stroke, bleeding, renal failure, and mediastinitis. At median follow-up of 5 years, there was no difference in long-term mortality (incidence rate ratio [IRR]:1.44; 95% CI, 0.83 to 2.51; P = 0.19), but CABG & AVR was associated with 73% lower risk of reoperation for AS (n = 13/485 versus n = 71/702; IRR: 0.27; 95% CI, 0.14 to 0.51; P < 0.001).

CONCLUSIONS

In patients undergoing CABG with mild-moderate AS, combining AVR with CABG was associated with no difference in operative mortality but with increased risk of stroke, bleeding, renal failure, and mediastinitis. Long-term mortality was not different, but a risk of reoperation for AS at 5 years was 73% lower. Given the increasingly wide availability and safety of transcatheter aortic valve replacement (TAVR), one may consider a conservative approach toward concomitant mild-moderate AS.

[Management of multiple valve disease]

Polyvalvular disease is not a rare condition, the lack of specific data for each situation does not allow perfoming standardized management and guidelines. We want to present by this review available data on the management of polyvalvular disease, taking into account different possible associations between the valve lesions.

Aortic valve surgery and survival in patients with moderate or severe aortic stenosis and left ventricular dysfunction

AIMS

We aimed to determine the frequency of aortic valve surgery (AVR) with or without coronary artery bypass grafting (CABG), among patients with moderate/severe aortic stenosis (AS) and left ventricular systolic dysfunction (LVSD), and its relationship with survival.

METHODS AND RESULTS

The Duke Echocardiographic Database (N = 132 804) was queried for patients with mean gradient ≥25 mmHg and/or peak velocity ≥3 m/s and LVSD (left ventricular ejection fraction ≤50%) from 1 January 1995-28 February 2014. For analyses purposes, AS was defined both by mean gradient and calculated aortic valve area (AVA) criteria. Time-dependent indicators of AVR in multivariable Cox models were used to assess the relationship of AVR and all-cause mortality. A total of 1634 patients had moderate (N = 1090, 67%) or severe (N = 544, 33%) AS by mean gradient criteria. Overall, 287 (26%) patients with moderate AS and 263 (48%) patients with severe AS underwent AVR within 5 years of the qualifying echo. There were 863 (53%) deaths observed up to 5 years following index echo. After multivariable adjustment in an inverse probability weighted regression model, AVR was associated with higher 5-year survival amongst patients with moderate AS and severe AS whether classified by AVA or mean gradient criteria. Over all, AVR ± CABG compared with medical therapy was associated with significantly lower mortality [hazard ratio, HR = 0.49 (0.38, 0.62), P < 0.0001]. Compared with CABG alone, CABG + AVR was associated with better survival [HR = 0.18 (0.12, 0.27), P < 0.0001].

CONCLUSIONS

In patients with moderate/severe AS and LVSD, mortality is substantial and amongst those selected for surgery, AVR with or without CABG is associated with higher survival. Research is required to understand factors contributing to current practice patterns and the possible utility of transcatheter approaches in this high-risk cohort.

Outcomes of cardiac surgery in the elderly

The elderly represent a rapidly growing and substantially under-treated sector in industrialized countries, with coronary artery disease and degenerative aortic stenosis rampant. The proportion of elderly patients undergoing cardiac surgery is rising steadily and outcomes continue to improve with the refinement of operative techniques and perioperative care. Advanced risk stratification models, such as the logistic European System for Cardiac Operative Risk Evaluation now offer validated prediction of operative mortality in these high-risk patients. Current trends towards off-pump coronary artery surgery, hybrid revascularization and mitral repair may have advantages in the elderly, who often have more diffuse cardiovascular disease and a lower tolerance to intervention. Recent advances may also provide surgical options for the emerging epidemics of cardiovascular disease affecting the elderly, atrial fibrillation and heart failure.

Changing strategy for aortic stenosis with coronary artery disease by transcatheter aortic valve implantation

Coronary artery disease (CAD) is combined with aortic stenosis (AS) in 40-50 % of patients with typical angina. Recently, transcatheter aortic valve implantation (TAVI) has changed the guideline for AS in patients with high comorbidity. At the same time more than 60 % of isolated CABG has been performed without cardiopulmonary bypass in Japan. CABG is recommended and should be considered in patients with primary indication for AVR and luminal stenosis >70 % in major coronary arteries and the left internal thoracic artery (LITA) by guidelines. AVR is indicated for severe AS undergoing CABG. It is generally accepted to perform AVR for moderate AS at the time of CABG by valve guidelines. However, prophylactic AVR for moderate AS associated with CABG may increase the early operative risk and expose the patients to postoperative long-term valve related complications. AVR after previous CABG poses potential risk for mortality and morbidity. The presence of patent ITA is a significant risk of its injury and difficulty of myocardial protection during aortic cross-clamping. Therefore, at present, for severe AS previous CABG with patent ITA should be one of the definite indications of TAVI. Rationale of TAVI in patients with severe AS and CAD has not been clearly delineated. The safety of TAVI irrespective of the extent and anatomy of CAD is still controversial. PCI is not appropriate before TAVI in high-risk patients with CAD. In the near future hybrid TAVI will be realistic considering least operative mortality and morbidity in high-risk patients.

Aortic valve and ascending aorta guidelines for management and quality measures: executive summary

The Society of Thoracic Surgeons Clinical Practice Guidelines are intended to assist physicians and other health care providers in clinical decision making by describing a range of generally acceptable approaches for the diagnosis, management, or prevention of specific diseases or conditions. These guidelines should not be considered inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the same results. Moreover, these guidelines are subject to change over time, without notice. The ultimate judgment regarding the care of a particular patient must be made by the physician in light of the individual circumstances presented by the patient.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.