Echocardiographic predictors of survival in low gradient aortic stenosis

Surgical aortic valve replacement for low-gradient aortic stenosis

AIMS

Low-gradient aortic stenosis is a challenging entity that needs accurate preoperative evaluation. For this high-risk patient population, ad hoc predictive scores are not available and profile risk is currently revealed by the EuroSCOREs. Aims of this study are to verify the suitability of the ES II as predictor of mortality in low-gradient aortic stenosis and to analyse the role of surgery as a treatment.

METHODS

From June 2013 to August 2019, 414 patients underwent surgical aortic valve replacement for low-gradient aortic stenosis. Mean age was 75.78 ± 6.77 years and 190 were women. The prognostic value of Logistic EuroSCORE and EuroSCORE II were compared by receiver-operating characteristics (ROC) curve analysis.

RESULTS

In-hospital, 30-day and 1-year mortality rates were respectively 3.4, 2.9 and 4.8% (14, 12 and 20 patients over 414). In-hospital mortality risk calculated by the Additive EuroSCORE was 7.2 ± 2.7%, by the Logistic EuroSCORE was 9 ± 5.2% and by the ES II was 4.13 ± 2.56%. The prognostic values of the EuroSCORE II and of the EuroSCORE were analysed in a ROC curve analysis for the prediction of in-hospital mortality [area under the curve (AUC): 0.62 vs. 0.58], 30-day mortality (AUC: 0.63 vs. 0.64) and 1-year mortality (AUC: 0.79 vs. 0.65). Both scores did not show significant differences with the only exception of 1-year mortality, for which EuroSCORE II had a better predictive ability than the Logistic EuroSCORE (P < 0.05).

CONCLUSION

In low-gradient aortic stenosis undergoing surgery, the EuroSCORE II is a strong predictor of 1-year mortality.

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.

Low-flow, low-gradient aortic stenosis with normal and depressed left ventricular ejection fraction

Low-flow, low-gradient (LF-LG) aortic stenosis (AS) may occur with depressed or preserved left ventricular ejection fraction (LVEF), and both situations are among the most challenging encountered in patients with valvular heart disease. In both cases, the decrease in gradient relative to AS severity is due to a reduction in transvalvular flow. The main challenge in patients with depressed LVEF is to distinguish between true severe versus pseudosevere stenosis and to accurately assess the severity of myocardial impairment. Paradoxical LF-LG severe AS despite a normal LVEF is a recently described entity that is characterized by pronounced LV concentric remodeling, small LV cavity size, and a restrictive physiology leading to impaired LV filling, altered myocardial function, and worse prognosis. Until recently, this entity was often misdiagnosed, thereby causing underestimation of AS severity and inappropriate delays for surgery. Hence, the main challenge in these patients is proper diagnosis, often requiring diagnostic tests other than Doppler echocardiography. The present paper proposes to review the diagnostic and therapeutic management specificities of LF-LG AS with and without depressed LV function.

New concepts in valvular hemodynamics: implications for diagnosis and treatment of aortic stenosis

Aortic valve stenosis (AS) is the third-most frequent heart disease after coronary artery disease and arterial hypertension, and it is associated with a high incidence of adverse outcomes. Recent data support the notion that AS is not an isolated disease uniquely limited to the valve. Indeed, AS is frequently associated with abnormalities of the systemic arterial system, and, in particular, with reduced arterial compliance, which may have important consequences for the pathophysiology and clinical outcome of this disease. Moreover, AS may also be associated with left ventricular systolic dysfunction and reduced transvalvular flow rate, which pose important challenges with regards to diagnostic evaluation and clinical decision making in AS patients. Hence, the assessment of AS severity, as well as its therapeutic management, should be conducted with the use of a comprehensive evaluation that includes not only the aortic valve, but also the systemic arterial system and the left ventricle because these three entities are tightly coupled from both a pathophysiological and a hemodynamic standpoint.

Valvular Aortic Stenosis in the Elderly

Elderly patients with valvular aortic stenosis have an increased prevalence of coronary risk factors, of coronary artery disease, and evidence of other atherosclerotic vascular diseases. Statins may reduce the progression of aortic stenosis (AS). Angina pectoris, syncope or near syncope, and congestive heart failure are the 3 classic manifestations of severe AS. Prolonged duration and late peaking of an aortic systolic ejection murmur best differentiate severe AS from mild AS on physical examination. Doppler echocardiography is used to diagnose the prevalence and severity of AS. The indications for cardiac catheterization and the medical management of AS are discussed. Once symptoms develop, aortic valve replacement (AVR) should be performed in patients with severe or moderate AS. Other indications for AVR are discussed. Warfarin should be administered indefinitely after AVR in patients with a mechanical aortic valve and in patients with a bioprosthetic aortic valve who have either atrial fibrillation, prior thromboembolism, left ventricular systolic dysfunction, or a hypercoagulable condition. Patients with a bioprosthetic aortic valve without any of these 4 risk factors should be treated with aspirin 75-100 mg daily.