Hypertension in aortic stenosis: relationship with revealed symptoms and functional measures on treadmill exercise

The safety of exercise for older patients with severe aortic stenosis undergoing conservative management: A narrative review

The incidence of aortic stenosis (AS) increases with age and is a serious problem in an aging society. In recent years, transcatheter aortic valve implantation (TAVI) has been performed widely; however, older patients may be ineligible for TAVI or surgical treatment because of medical ineligibility. Symptom-based rehabilitation is required for these patients to maintain and improve their physical function and ability to perform activities of daily living. No studies have examined exercise safety for older patients with severe AS who are ineligible for TAVI or surgery. We summarized the safety of exercise for older patients with severe AS, collecting 7 studies on maximal exercise stress tests and 16 studies on preoperative physical examinations. From this review, it may be unlikely that exercise under appropriate management can cause hemodynamic changes, leading to death. However, there were no studies on exercise intervention for older patients with AS who are chosen for conservative management. The optimal exercise intensity for symptomatic older patients with AS undergoing conservative management and the effects of continuous exercise intervention require future study.

Arterial Hypertension in Aortic Valve Stenosis: A Critical Update

Aortic stenosis (AS) is a very common valve disease and is associated with high mortality once it becomes symptomatic. Arterial hypertension (HT) has a high prevalence among patients with AS leading to worse left ventricle remodeling and faster degeneration of the valve. HT also interferes with the assessment of the severity of AS, leading to an underestimation of the real degree of stenosis. Treatment of HT in AS has not historically been pursued due to the fear of excess reduction in afterload without a possibility of increasing stroke volume due to the fixed aortic valve, but most recent evidence shows that several drugs are safe and effective in reducing BP in patients with HT and AS. RAAS inhibitors and beta-blockers provide benefit in selected populations based on their profile of pharmacokinetics and pharmacodynamics. Different drugs, on the other hand, have proved to be unsafe, such as calcium channel blockers, or simply not easy enough to handle to be recommended in clinical practice, such as PDE5i, MRA or sodium nitroprusside. The present review highlights all available studies on HT and AS to guide antihypertensive treatment.

Left atrial volume index predicts adverse events in asymptomatic moderate or severe aortic stenosis

OBJECTIVE

In aortic stenosis (AS), chronic pressure overload on left ventricle (LV) leads to LV hypertrophy, impaired relaxation, increased chamber stiffness, fibrosis and left atrial (LA) dilatation. An enlarged LA may be a marker of longstanding diastolic dysfunction (DD) and more advanced disease in AS. We aimed to assess the impact of LA volume index (LAVI) on events in patients with moderate or severe AS.

METHODS

A total of 324 patients (mean age 69 ± 13 years, 61% men) were included. LA volume was measured by biplane Simpson's method using apical four- and two-chamber views and indexed to body surface area. An increased LAVI was defined as > 34 ml/m² .

RESULTS

The mean EF was 64 ± 8%, LAVI 35 ± 14 ml/m² and flow rate 244 ± 70 ml/s. The number of total events was 275 (85%): 243 (75%) aortic valve replacement and 32 (10%) deaths. Mean follow-up 23.7 ± 23.8 months (median 15.2 months). An increased LAVI (45% [n = 145]) was associated with adverse events (HR 1.86; 95% CI 1.24-2.82, p = 0.003) independent of age, smoking, diabetes, atrial fibrillation, LV ejection fraction, LV mass, aortic valve area, and low flow rate (<200 ml/s). In the same multivariate model, when increased LAVI was replaced by E/e' ratio ≥14 cm, no association was found between E/e' ratio ≥14 cm and adverse events (HR 1.18; 95% CI .78-1.78, p = 0.430).

CONCLUSION

LAVI was an independent predictor of adverse events in patients with moderate or severe AS and preserved ejection fraction. Including LAVI in the risk assessment of AS patients may further improve risk stratification.

Ageing, hypertension and aortic valve stenosis - Understanding the series circuit using cardiac magnetic resonance and applanation tonometry

BACKGROUND

Aortic stenosis (AS) is no longer considered to be a disease of fixed left ventricular (LV) afterload, but rather, functions as a series circuit, with important contributions from both the valve and vasculature. Patients with AS are typically elderly, with hypertension and a markedly remodelled aorta. The arterial component is sizeable, and yet, quantifying this to-date has been difficult to determine. We compared measurement of aortic pressure, flow and global LV load using a cardiac magnetic resonance (CMR)/applanation tonometry (AT) technique to uncouple ventriculo-arterial (VA) interactions.

METHODS

20 healthy elderly patients and 20 with AS underwent a CMR/AT protocol. CMR provided LV volume and aortic flow simultaneously with AT pressure acquisition. Aortic pressure was derived by transformation of the AT waveform. Systemic vascular resistance (SVR) and global LV load were determined as the relationship of pressure to flow in the frequency domain. Values from both cohorts were compared.

RESULTS

AS patients were older (p ​< ​0.01) albeit with no significant difference in brachial or central aortic pressure. SVR (14228 vs 19906 ​dyne ​s.cm-3; p ​= ​0.02) and load (740 vs 946 ​dyne ​s.cm-3; p ​= ​0.02) were higher in patients with AS, whilst aortic peak flow velocity was lower (38 vs 58 ​cm/s; p ​< ​0.01).

CONCLUSIONS

Quantification of aortic pressure, flow velocity and global LV load using a simultaneous CMR/AT technique is able to demonstrate the progressive effects of hypertension and aortic stiffening with advanced age and valvular stenosis. This technique may help to better identify future patients at risk of VA coupling mismatch after correction of AS.

Hypertension in aortic stenosis: a focused review and recommendations for clinical practice

: In patients with aortic stenosis, the presence of hypertension negatively affects the hemodynamic severity of the stenosis, and worsens adverse left ventricular remodeling. It accelerates the progression of the stenosis and is associated with worse prognosis. Proper management of hypertension is thus crucial but there are concerns about the safety and efficacy of antihypertensive medications as well as uncertainty about optimal blood pressure (BP) targets and their impact on left ventricular mass regression and survival benefits. In the present review, we discuss these issues based on the evidence available in the current literature. Focus is first directed on the consequences of a persistently elevated BP before and after surgical aortic valve replacement or transcatheter valve implantation, and the clinical significance of an abnormal BP response during exercise in patients with significant aortic stenosis. Available data on use of antihypertensive drugs are then critically addressed, the conclusion being that calcium channel blockers may be associated with lower survival, and that diuretics may have disadvantages in patients with left ventricular hypertrophy and smaller left ventricular cavity dimensions, β-blockers may be well tolerated and a better choice for patients with concomitant coronary artery disease and arrhythmias. Renin--angiotensin system blockers improve survival given either before or after valve intervention. Emphasis is placed on the fact that evidence is not derived from randomized trials but only from observational studies. Finally, we discuss the optimal SBP level to reach in patients with aortic stenosis. Again, randomized trials are not available but observational evidence suggests that values between 130 and 139 mmHg systolic and 70-90 mmHg diastolic might represent the best option, and lower BP targets should probably be avoided.

Sex-differences in aortic stenosis: Effect on functional capacity and prognosis

BACKGROUND

The patterns of left ventricular (LV) remodeling in aortic stenosis (AS) are different in men and women. We aimed to assess whether there were also sex differences in measurements obtained on exercise testing.

METHODS

Echocardiography and ETT (modified Bruce) were performed at presentation in 316 patients with moderate or severe AS. An early rapid rise in heart rate (RR-HR) during ETT was defined as achieving at least 85% of target heart rate or ≥50% increase from baseline within the first 6 min.

RESULTS

Mean age was 66 ± 12 years in men (n = 212) and 65 ± 12 years in women (n = 104) (p = NS). Men walked longer than women on the treadmill (10.4 ± 4.3 vs. 8.2 ± 4.2 min, p < 0.001) and achieved higher METs (9.2 ± 4.5 vs. 7.6 ± 4.3, p < 0.001), but both sexes achieved similar levels of peak heart rate and blood pressure. During a mean follow up of 34.9 ± 34.6 months, 29 deaths occurred (20 in men and 9 in women, p = 0.821). Age and body mass index were strong determinants of lower METs in men, but not in women, while Zva was a determinant in women but not in men. RR-HR was a strong determinant of lower METs in both sexes. Event-free survival was significantly lower in men with RR-HR but not in women.

CONCLUSION

Exercise capacity was lower in women than men, and the determinants of exercise capacity differed. An RR-HR was a strong determinant of lower METs in both sexes, but predicted all-cause mortality only in men.