Outpatient management of heart valve disease following the COVID-19 pandemic: implications for present and future care.

The established processes for ensuring safe outpatient surveillance of patients with known heart valve disease (HVD), echocardiography for patients referred with new murmurs and timely delivery of surgical or transcatheter treatment for patients with severe disease have all been significantly impacted by the novel coronavirus pandemic. This has created a large backlog of work and upstaging of disease with consequent increases in risk and cost of treatment and potential for worse long-term outcomes. As countries emerge from lockdown but with COVID-19 endemic in society, precautions remain that restrict 'normal' practice. In this article, we propose a methodology for restructuring services for patients with HVD and provide recommendations pertaining to frequency of follow-up and use of echocardiography at present. It will be almost impossible to practice exactly as we did prior to the pandemic; thus, it is essential to prioritise patients with the greatest clinical need, such as those with symptomatic severe HVD. Local procedural waiting times will need to be considered, in addition to usual clinical characteristics in determining whether patients requiring intervention would be better suited having surgical or transcatheter treatment. We present guidance on the identification of stable patients with HVD that could have follow-up deferred safely and suggest certain patients that could be discharged from follow-up if waiting lists are triaged with appropriate clinical input. Finally, we propose that novel models of working enforced by the pandemic-such as increased use of virtual clinics-should be further developed and evaluated.

Higher left ventricular mass-wall stress-heart rate product and outcome in aortic valve stenosis.

OBJECTIVE: Whether increased myocardial oxygen demand could help explain the association of left ventricular (LV) hypertrophy with higher adverse event rate in patients with aortic valve stenosis (AS) is unknown. METHODS: Data from 1522 patients with asymptomatic mostly moderate AS participating in the Simvastatin-Ezetimibe in AS study followed for a median of 4.3 years was used. High LV mass-wall stress-heart rate product was identified as >upper 95% CI limit in normal subjects. The association of higher LV mass-wall stress-heart rate product with major cardiovascular (CV) events, combined CV death and hospitalised heart failure and all-cause mortality was tested in Cox regression analyses, and reported as HR and 95% CI. RESULTS: High LV mass-wall stress-heart rate product was found in 19% at baseline, and associated with male sex, higher body mass index, hypertension, LV hypertrophy, more severe AS and lower LV ejection fraction (all p<0.01). Adjusting for these confounders in time-varying Cox regression analysis, 1 SD higher LV mass-wall stress-heart rate product was associated with higher HR of major CV events (HR 1.16(95% CI 1.06 to 1.29)), combined CV death and hospitalised heart failure (HR 1.29(95% CI 1.09 to 1.54)) and all-cause mortality (HR 1.34(95% CI 1.13 to 1.58), all p<0.01). CONCLUSION: In patients with initially mild-moderate AS, higher LV mass-wall stress-heart rate product was associated with higher mortality and heart failure hospitalisation. Our results suggest that higher myocardial oxygen demand is contributing to the higher adverse event rate reported in AS patients with LV hypertrophy. TRIAL REGISTRATION NUMBER: NCT000092677;Post-results.

Exercise testing in patients with asymptomatic moderate or severe aortic stenosis.

OBJECTIVE: To assess the safety and tolerability of treadmill exercise testing and the association of revealed symptoms with outcome in apparently asymptomatic patients with moderate to severe aortic stenosis (AS). METHODS: A retrospective cohort study of 316 patients (age 65±12 years, 67% men) with moderate and severe AS who underwent echocardiography and modified Bruce exercise treadmill tests (ETTs) at a specialist valve clinic. The outcome measures were aortic valve replacement (AVR), all-cause mortality or a composite of AVR and all-cause mortality. RESULTS: At baseline, there were 210 (66%) patients with moderate and 106 (34%) with severe AS. There were 264 (83%) events. 234 (74%) patients reached an indication for AVR, 145 (69%) with moderate and 88 (83%) with severe AS (p<0.05). Of the 30 (9%) deaths recoded during follow-up, 20 (67%) were cardiovascular related. In total, 797 exercise tests (mean 2.5±2.1 per patient) were performed. No serious adverse events were observed. The prevalence of revealed symptoms at baseline ETT was 29% (n=91) and was significantly higher in severe AS compared with moderate AS (38%vs23%, p=0.008). Symptoms were revealed in 18%-59% of patients during serial ETT conducted over a follow-up period of 34.9 (SD 35.1) months. The event-free survival at 24 months with revealed symptoms was 46%±4% and without revealed symptoms was 70%±4%. CONCLUSIONS: ETT in patients with moderate or severe AS is safe and tolerable. Serial exercise testing is useful to reveal symptoms not volunteered on the history and adds incremental prognostic information to baseline testing.

Take home messages with cases from focused update on echocardiographic assessment of aortic stenosis.

Echocardiography plays an important role in the assessment of valvular aortic stenosis. Updated recommendations focusing on a stepwise approach to evaluating aortic stenosis have recently been published by the European Association of Cardiovascular Imaging and the American Society of Echocardiography. This review uses illustrative cases to demonstrate technical aspects of aortic stenosis assessment and use of the new proposed classification scheme for aortic stenosis. Key points from the updated recommendations reviewed in this paper are: (1) technical considerations and sources of error in measurement of peak velocity, mean aortic valve gradient and aortic valve area by continuity equation. (2) Application of flow status using indexed left ventricular stroke volume to distinguish patients with low gradients and a low calculated aortic valve area. (3) Use of low-dose dobutamine stress echocardiography in patients with low ejection fraction. (4) Application of the new classification scheme and review of algorithm use for echocardiographic evaluation of severe aortic stenosis. Improved understanding of how to handle unmatched variables and adopting an integrated approach to determine severity is central to guiding the clinician's management of aortic stenosis.

Impact of baseline severity of aortic valve stenosis on effect of intensive lipid lowering therapy (from the SEAS study).

Retrospective studies have suggested a beneficial effect of lipid-lowering treatment on the progression of aortic stenosis (AS) in milder stages of the disease. In the randomized, placebo-controlled Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, 4.3 years of combined treatment with simvastatin 40 mg and ezetimibe 10 mg did not reduce aortic valve events (AVEs), while ischemic cardiovascular events (ICEs) were significantly reduced in the overall study population. However, the impact of baseline AS severity on treatment effect has not been reported. Baseline and outcomes data in 1,763 SEAS patients (mean age 67 years, 39% women) were used. The study population was divided into tertiles of baseline peak aortic jet velocity (tertile 1: ≤ 2.8 m/s; tertile 2: > 2.8 to 3.3 m/s; tertile 3: > 3.3 m/s). Treatment effect and interaction were tested in Cox regression analyses. The rates of AVEs and ICEs increased with increasing baseline severity of AS. In Cox regression analyses, higher baseline peak aortic jet velocity predicted higher rates of AVEs and ICEs in all tertiles (all p values < 0.05) and in the total study population (p < 0.001). Simvastatin-ezetimibe treatment was not associated with a statistically significant reduction in AVEs in any individual tertile. A significant quantitative interaction between the severity of AS and simvastatin-ezetimibe treatment effect was demonstrated for ICEs (p < 0.05) but not for AVEs (p = 0.10). In conclusion, the SEAS study results demonstrate a strong relation between baseline the severity of AS and the rate of cardiovascular events but no significant effect of lipid-lowering treatment on AVEs, even in the group with the mildest AS.