Outcome and impact of surgery in paradoxical low-flow, low-gradient severe aortic stenosis and preserved left ventricular ejection fraction: a cardiac catheterization study.

BACKGROUND: The clinical relevance and management of paradoxical low-flow, low-gradient aortic stenosis (LFLG-AS) with preserved left ventricular ejection fraction remain debated. The aim of this study is to determine the features and outcome of LFLG-AS assessed using cardiac catheterization. METHODS AND RESULTS: Between 2000 and 2010, 768 patients with preserved left ventricular ejection fraction (>50%) and severe AS (valve area ≤ 1 cm(2)) without other valvular disease underwent cardiac catheterization. Mean age was 74 ± 8 years, 42% were women, and 46% had associated coronary artery disease. The prevalence of LFLG (indexed left ventricular stroke volume <35 mL/m(2) and mean gradient <40 mm Hg), normal flow high gradient, normal flow low gradient, and low flow high gradient were 13%, 50%, 22%, and 15%, respectively. Compared with patients with normal flow high gradient, those with LFLG were significantly older, with significantly reduced systemic arterial compliance and vascular resistances and increased valvulo-arterial impedance (all P<0.05). Ten-year survival was reduced in LFLG-AS (32 ± 9%) compared with normal flow high gradient (66 ± 4%; P=0.0002). After adjustment for other risk factors, LFLG-AS was independently associated with reduced long-term survival (hazard ratio, 1.85; 95% confidence interval, 1.08-3.07; P=0.02). However, despite higher operative mortality, patients with LFLG-AS undergoing aortic valve replacement seemed to have better long-term survival than those managed conservatively (5-year survival rate: 63 ± 6% versus 38 ± 15%; P=0.007; hazard ratio, 0.23; 95% confidence interval, 0.09-0.59; P=0.002). CONCLUSIONS: This large cardiac catheterization-based study reports that the LFLG-AS entity is not rare and is associated with worse outcome whether treated medically or surgically. However, these patients may have better long-term survival if treated surgically. Further prospective studies are needed to confirm this finding.

Impact of Pulmonary Hypertension on Outcome in Patients with Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction.

AIMS: The prognostic impact of elevated pulmonary arterial pressure (PAP) remains controversial in aortic stenosis (AS) and few studies focused on patients with preserved left ventricular ejection fraction (LVEF). We aimed to investigate the impact of pulmonary hypertension (PH), invasively derived, on survival in severe AS with preserved LVEF. METHODS AND RESULTS: Between 2000 and 2010, 749 patients (74 ± 8 years, 57% males) with preserved LVEF and severe AS without other valvular heart disease underwent cardiac catheterization. PH was defined as mean PAP > 25 mmHg. The mean follow-up was 4.6 ± 3.0 years. Overall, 32% (n = 241) of patients had PH. Surgical aortic valve replacement (SAVR) was performed in 91% of patients with 4.5% of 30-day mortality rate, significantly higher in patients with PH than without PH (7.5 vs. 3.5%, p = 0.014). In logistic regression, PH was an independent predictor of increased 30-day mortality (odds-ratio = 2.2, p = 0.04). Overall long-term survival was significantly reduced in patients with PH as compared to those without (10-year: 52 ± 5 vs. 68 ± 3%, p < 0.0001). Likewise, focusing on patients with SAVR showed significant reduced survival in those with PH (10-year: 57 ± 5 vs. 72 ± 3%, p < 0.0001). In multivariate analysis, after adjustment for relevant cofactors, PH was an independent predictor of mortality (hazard ratio = 1.5, p = 0.009). Using quartiles of mean PAP, only patients with most elevated values (Q4: mean PAP: 27-67mmHg) had significantly reduced survival, as compared to other quartiles (all p < 0.0001). CONCLUSION: In patients with severe AS and preserved LVEF, PH is an independent predictor of 30-day and long-term mortality patients. Nevertheless, only severely elevated PAP seems associated with reduced survival.

Prognostic impact of global left ventricular hemodynamic afterload in severe aortic stenosis with preserved ejection fraction.

INTRODUCTION: Global left ventricular (LV) afterload as assessed by valvulo-arterial impedance (Zva), may be an independent predictor of mortality in patients with severe aortic stenosis (AS) and preserved LV ejection fraction (LVEF). However, its quantification using echocardiography may be subject to error measurement. We aimed to determine the prevalence and impact on long-term survival of high Zva, purposely measured by cardiac catheterization. METHODS AND RESULTS: 676 patients with preserved LVEF and severe AS without other valvular heart diseases underwent cardiac catheterization. Zva was derived from catheterization and calculated as follows: mean aortic gradient+systolic blood pressure/indexed LV stroke volume. Zva was considered high when >5mmHg/mL/m(2) based on previous studies. Overall, high Zva was found in 42% of all AS patients. Four-year survival and 8-year survival were significantly reduced in patients with high Zva (74±3% and 57±4%) as compared to those with low Zva (85±2% and 74±3%; p=0.002). After adjustment for all other risk factors, Zva was independently associated with reduced long-term survival (hazard ratio [HR]=1.47 95% CI: 1.04-2.09; p=0.029). Of interest, high Zva remained associated with reduced survival as compared to low Zva, in patients with normal LV stroke volume, but was no longer significant in low flow patients (p=0.98). CONCLUSION: High Zva, estimated invasively in our study, is frequent in patients with severe AS, and appears as a robust and independent predictor of survival. Zva should be used as an additional parameter for risk stratification of severe AS, more particularly in patients with normal flow.

Prognosis importance of low flow in aortic stenosis with preserved LVEF.

AIMS: Previous studies using echocardiography suggested that a low flow (LF) defined as an indexed stroke volume (SVi) <35 mL/m(2) may be an important determinant of outcome in patients with severe aortic stenosis (AS). We sought to assess the prognostic importance of stroke volume derived from invasive data. The aim of this study was to determine the impact of LF, purposely derived from cardiac catheterisation data, on outcome of patients with severe AS and preserved LVEF. METHODS: Between 2000 and 2010, 768 patients with preserved LVEF (>50%) and severe AS (valve area ≤1 cm(2)) without other valvular heart disease underwent cardiac catheterisation. The long-term overall mortality was assessed as the primary end-point. RESULTS: Mean age was 74±8 years, 58% were men, 46% had coronary artery disease and mean LVEF was 72±10%. Low SVi was found in 27% (n=210) of patients with AS. As compared with patients with normal SVi, those with low SVi were significantly older (p<0.0001) with higher rate of atrial fibrillation (p<0.0001). Additionally, they had lower LVEF (p=0.046), aortic valve area (p<0.0001), mean pressure gradient (p<0.0001), systemic arterial compliance (p<0.0001) and higher systemic vascular resistances (p<0.0001). Eight-year survival was significantly reduced in patients with low SVi as compared with those with normal SVi (51±5% vs 67±3%; p<0.0001). After adjustment for all other risk factors, reduced SVi was independently associated with long-term mortality (HR=1.45, 95% CI 1.1 to 2.1; p=0.048). CONCLUSIONS: In patients with severe AS and preserved LVEF, LF, as assessed using cardiac catheterisation is frequent, and is an independent predictor of mortality. Consequently, the measurement of SVi should be systematically included in the assessment of these patients.