Introduction
A common condition is known as mixed aortic valve disease (MAVD), which is characterized by both aortic stenosis (AS) and aortic regurgitation (AR). Although there is mounting evidence that the prognosis is bad, little information is available in the literature, and it is still being determined when to intervene best in asymptomatic patients.
What Is the Epidemiology and Etiology of Mixed Aortic Valve Disease?
Multiple and mixed valvular heart disease (VHD) accounted for 10.4 percent of all VHD diagnoses in a Swedish population-wide registry. In these situations, AS was the lesion most frequently linked to AR (17.9 percent of all AR). In comparison, AR was the lesion most frequently linked to AS (6.8 percent of all AS). The most common causes of MAVD are congenital (mostly bicuspid) and degenerative valve disorders. Aortic valve replacement was performed in 67 percent of patients in a group of 524 initially asymptomatic people with MAVD (mean age 66 years) with a mean follow-up time of 5.5 years. In these surgical instances, the pathology of the valve was degenerative in 53 percent, congenital in 37 percent, and rheumatic in 9 percent.
Only in patients with predominant AR was bicuspid valve disease the most common cause. However, the prevalence of rheumatic disease in a given area and the population's average age significantly impact the proportion of rheumatic, congenital, and degenerative etiologies among patients who had both AS and AR. Severe AS or severe AR was seen in 52 percent of patients, whereas combined severe AS and severe AR were less common (11 percent). In addition, it was found that 36 percent of patients had moderate AS or moderate AR without severe lesions at presentation, including 25 percent with moderate AS and moderate AR.
What Are the Outcomes and History of Mixed Aortic Valve Disease?
Only in the past ten years has the bad prognosis of MAVD patients been brought to light. Concomitant moderate or severe AR was an independent predictor of adverse outcomes in a random study, retrospective series of 306 consecutive individuals with severe AS for whom non-surgical therapy was planned. Aortic valve replacement became necessary for 50 individuals throughout a median follow-up of 8.9 years. A peak aortic velocity of fewer than four m/s, which is a marker of the severity of both lesions, was a significant predictor of prognosis, which is interesting because stratifying patients based on the severity of AS and AR was not predictive of the need for a subsequent aortic valve replacement.
In a different series, over a 5.5-year follow-up period, 17 percent of 524 initially asymptomatic persons with MAVD who were 66 years old on average required aortic valve replacement, and 67 percent of them passed away. It took an average of 4 years for an aortic valve replacement or death to occur. In a retrospective series, it was found that 81 percent of 213 asymptomatic patients with a mean age of 69 years and a combination of at least moderate AS and moderate AR developed severe symptoms, underwent aortic valve replacement, or passed away throughout a mean follow-up of 10.1 years. Only 2.9 years passed on average before the bad event occurred.
According to the research, people with MAVD should receive the same frequency of monitoring as asymptomatic patients with severe AS. Regardless of the aortic valve area and symptom condition, a substantial decrease in death rates following aortic valve replacement was seen. Even after an aortic valve replacement, there was a significant risk of death, highlighting the potential value of an early intrusive approach. Progression primarily stems from AS advancement in patients with MAVD. The severity of AR does not seem to change noticeably over time, and it could potentially regress and turn into AS.
What Is the Treatment of Mixed Aortic Valve Disease?
It is advised that a multidisciplinary cardiac team make these decisions because managing patients with MAVD and choosing the best time for intervention are difficult undertakings.
Follow the most recent recommendations created for isolated severe lesions when it is severe AS and severe AR. To identify the subset of patients with hemodynamically significant valve disease at higher risk under conservative treatment in patients with a combination of moderate AS and moderate AR, careful assessment of the overall hemodynamic impact must take precedence over determining the severity of AS and AR. This evaluation should not be restricted to looking at LV (left ventricle) dilatation and dysfunction and the existence of symptoms. Exercise testing should be used frequently to reveal hidden symptoms.
In MAVD, several echocardiographic characteristics have been linked to poor outcomes. Although the additional function of natriuretic peptides in the context of MAVD has not been specifically investigated, it is likely that, as has been demonstrated in isolated AS and AR, these biomarkers reflect the overall severity of the disease and may therefore help direct the clinician. Patients with normal preoperative LV function may develop postoperative LV dysfunction. Moreover, mounting evidence shows that aortic valve replacement may enhance prognosis without regard to symptoms, reinforcing the need for early surgery. Uncertainty exists over the effectiveness of using the extra markers to signal early surgery; randomized studies in asymptomatic patients would be required to assess this possibility.
Decision-making for individuals with MAVD and bicuspid valve disease must incorporate an evaluation of the aortic root. Suppose the diameter of the ascending aorta is higher than 4.5 cm. In that case, current recommendations support replacing the ascending aorta in patients with a bicuspid aortic valve who are having aortic valve surgery due to aortic valve disease. Aortic valve replacement is also reasonable for patients with moderate AS or AR who have other cardiac procedures, such as surgery on the ascending aorta. However, there is currently no data to help guide this procedure for patients with MAVD who have mild AS and AR. The ideal valvular substitute in MAVD, but it is important to note that patients with MAVD before transcatheter aortic valve replacement (TAVR) appear to have a post-TAVR survival advantage compared to patients with pure AS before TAVR, suggesting that the LV has adapted to the paravalvular leak caused by the TAVR procedure better than it has to pure AS. However, not all studies have found this protective effect of preexisting AR on survival following TAVR.
Conclusion
Recent research has shown that untreated MAVD significantly affects outcomes, especially for people with mild AS and moderate AR. The diagnosis of MAVD can be difficult and calls for a careful analysis of each lesion, taking into account the unique dangers of MAVD and a comprehensive assessment of the valvular disease's overall effects. Multimodality imaging, such as MDCT (multidetector computed tomography) and MRI (magnetic resonance imaging), may be necessary for several clinical situations to evaluate AS and AR.
