Prevalence, clinical and echocardiographic characteristics of various flow and gradient patterns in mild or moderate aortic stenosis with normal left ventricular ejection fraction

BACKGROUND/OBJECTIVES

Paradoxical low-flow aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) has only been described in severe AS. Controversy surrounds prognosis and management but no studies have reported this phenomenon in mild or moderate AS. We investigated the prevalence of flow and gradient patterns in this population, characterising their clinical and echocardiographic profile.

METHODS

Consecutive subjects (n=1362) with isolated AS: mild (n=462, aortic valve area≥1.5cm(2), 2.5m/s<aortic jet velocity≤3m/s) or moderate (n=900, 1cm(2)≤aortic valve area<1.5cm(2)) and normal LVEF (≥50%) were studied. Subjects with low-flow (stroke volume index<35ml/m(2)) were identified. Univariate and multivariate analyses were employed to compare the flow and gradient patterns.

RESULTS

In mild AS, 130 (28%) had low-flow. Lower left ventricular mass index (LVMI) (97.0±28.5vs116.4±2.3g/m(2),p<0.001), higher percentage of concentric remodelling (40%vs6%,p<0.001) and hypertrophy (43%vs40%,p<0.001) and lower end-systolic wall stress (ESWS) (57.6±1.60vs67.7±19.6dyn/cm(2),p=0.014) were independently associated with low-flow. Similarly, in moderate AS, 297 (33%) had low-flow. Older age (73.4±14.8vs69.5±16.5,p=0.027), lower LVMI (88.6±25.9vs118.0±36.5,p<0.001), higher percentage of concentric remodelling (46%vs8%,p<0.001) and lower ESWS (59.9±18.3vs70.5±19.7,p<0.001) were independently associated with low-flow. Despite moderate AS, most had lower mean pressure gradients, especially subjects with concentric remodelling. In the entire cohort, low-flow patients had more concentric remodelling (43%vs7%,p<0.001) and less eccentric hypertrophy (2%vs27%,p<0.001) compared to normal flow.

CONCLUSIONS

Low-flow AS with normal LVEF is observed in mild or moderate AS, in up to a third of the cases. These patients had different LV structure compared to normal-flow, with more concentric remodelling. Further studies are warranted.

Assessment of left ventricular myocardial performance by tissue Doppler echocardiography in patients with polycythemia vera

AIMS

The aim of this study was to evaluate myocardial performance index (MPI) which reflects the combined systolic and diastolic performance of the ventricles by tissue Doppler imaging (TDI) in patients with polycythemia vera (PV).

METHOD AND MATERIALS

Twenty-eight patients with PV (17 men; mean age 60±9 years) and 30 age-matched healthy subjects were prospectively evaluated. The diagnosis of PV was performed according to the World Health Organization (WHO) criteria. Left ventricular (LV) systolic and diastolic functions were assessed by conventional echocardiography and TDI. MPI of both the LV and right ventricles (RV) were measured by TDI method.

RESULTS

The LV MPI was significantly higher in PV group than in the controls (0.61±0.16 vs. 0.49±0.05; P=0.001). Also, the RV MPI was impaired in patients with PV compared to the control subjects (0.51±0.11 vs. 0.43±0.09; P=0.005). RV late A filling velocity (Am) and RV isovolumetric relaxation time were significantly higher in the PV group compared to healthy subjects (P=0.03 and 0.05, respectively). In logistic regression models, PV was determined as an independent predictor of impaired MPI (odds ratio: 3.7; CI 95%, 1.2-7.5). In addition, pulmonary arterial pressure was significantly elevated in patients with PV compared to the controls (P=0.02).

CONCLUSION

This study demonstrated that biventricular MPI is impaired in patients with PV.