Timing of surgery in aortic stenosis

Natural progression of low-gradient severe aortic stenosis with preserved ejection fraction

Because the natural progression of low-gradient aortic stenosis (LGAS) has not been well defined, we performed a retrospective study of 116 consecutive patients with aortic stenosis who had undergone follow-up echocardiography at a median interval of 698 days (range, 371-1,020 d). All patients had preserved left ventricular ejection fraction (>0.50) during and after follow-up. At baseline, patients were classified by aortic valve area (AVA) as having mild stenosis (≥1.5 cm(2)), moderate stenosis (≥1 to <1.5 cm(2)), or severe stenosis (<1 cm(2)). Severe aortic stenosis was further classified by mean gradient (LGAS, mean <40 mmHg; high-gradient aortic stenosis [HGAS], mean ≥40 mmHg). We compared baseline and follow-up values among 4 groups: patients with mild stenosis, moderate stenosis, LGAS, and HGAS. At baseline, 30 patients had mild stenosis, 54 had moderate stenosis, 24 had LGAS, and 8 had HGAS. Compared with the moderate group, the LGAS group had lower AVA but similar mean gradient. Yet the actuarial curves for progressing to HGAS were significantly different: 25% of patients in LGAS reached HGAS status significantly earlier than did 25% of patients in the moderate-AS group (713 vs 881 d; P=0.035). Because LGAS has a high propensity to progress to HGAS, we propose that low-gradient aortic stenosis patients be closely monitored as a distinct subgroup that warrants more frequent echocardiographic follow-up.

Anesthetic Considerations in the Patient With Valvular Heart Disease Undergoing Noncardiac Surgery

Valvular heart disease can be an important finding in patients presenting for noncardiac surgery. Valvular heart disease and resulting comorbidity, such as heart failure or atrial fibrillation, significantly increase the risk for perioperative adverse events. Appropriate preoperative assessment, adequate perioperative monitoring, and early intervention, should hemodynamic disturbances occur, may help prevent adverse events and improve patient outcome. This review article aims to guide the practitioner in the various aspects of anesthetic management in the perioperative care of patients with valvular heart disease. The pharmacological approach to optimization of patient outcome with drugs, such as βblockers and lipid-lowering medications (statins), is an evolving field, and recent developments are discussed in this article.

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

Mild to moderate aortic stenosis is a common finding in patients presenting for coronary artery bypass grafting (CABG), and its management is controversial. However, review of available data suggests a surgical strategy for these patients. Recent data demonstrate that 1) progression of aortic stenosis is more rapid in those with leaflet calcification; 2) the addition of aortic valve replacement to CABG in patients with mild to moderate stenosis does not increase hospital mortality when compared with bypass surgery alone; 3) hospital mortality for aortic valve replacement after previous bypass surgery has declined in recent years; 4) aortic valve replacement places the patient at risk for prosthesis-related complications; 5) the limited 10-year survival (competing risk of death) leaves only a minority of individuals with mild aortic stenosis alive and eligible for aortic valve replacement 10 years after bypass surgery; and 6) combined aortic valve replacement and CABG confers a survival benefit in those with moderate aortic stenosis but not in those with mild aortic stenosis. Therefore, in the coronary artery bypass patient with moderate aortic stenosis, leaflet calcification, and life expectancy greater than 5 years, concomitant aortic valve replacement is advised. In contrast, aortic valve replacement is rarely indicated in those with mild aortic stenosis.

Is measurement of plasma brain natriuretic peptide levels a useful test to detect for surgical timing of valve disease?

BACKGROUND

The optimal timing of valve surgery is very important. In patients who are severely symptomatic, the marked improvement in symptomatic status observed following successful valve surgery. However, in patients with no or only mild symptoms, the decision is more difficult. The aim of this retrospective study was to determine whether the measurement of plasma brain natriuretic peptides (BNP) levels is useful to decide surgical timing for valve disease.

METHODS

Fifty-one patients with valve disease underwent single valve surgery (mitral stenosis, MS, 13; mitral regurgitation, MR, 16; aortic stenosis, AS, 14; aortic regurgitation, AR, 8 patients). Blood samples, echocardiographic and cardiac catheterization data were obtained before operation and echocardiographic examination were performed after 1-year of operations.

RESULTS

In patients subjected to single heart valve surgery, plasma BNP mean levels were 214.6+/-48.5 pg/ml. In plasma BNP levels, there was only significant difference between MS and AS group (MS 67.5+/-9.7 vs. AS 314.3+/-112.0 pg/ml, P=0.04). There were no relationships between plasma BNP levels and pre-operative cardiac functions. After 1-year of the valve surgery, NYHA functional class was reduced in 36 patients (70.6%) and plasma BNP levels before the surgery significantly correlated with post-operative NYHA functional class.

CONCLUSIONS

In this retrospective study, patients with high plasma BNP levels significantly impaired the improvement of clinical symptoms after surgery. We have suggested that plasma BNP levels is useful for detecting asymptomatic valvular disease, and is a clinical marker useful in determining the optimal surgical timing.

Timing of Aortic Valve Surgery in Chronic Aortic Stenosis and Regurgitation

The correct timing of aortic valve replacement in chronic aortic stenosis or regurgitation is a very important and sometimes difficult task for physicians caring for patients with aortic valve disease. In this review, we will present the current available literature regarding the appropriate management of these patients.