Plugging Holes Expanding Horizon for Structural Interventions

Half a century ago, replacement of diseased heart valves with an artificial prosthesis ushered a new era in the cardiovascular medicine. New solutions to complex problems frequently create new problems of their own that require innovative solutions. Paraprosthetic regurgitation through an opening between the prosthesis and the annulus of the valve is one such challenge. Although much less frequent, pseudoaneurysm of the heart is another one. For decades, the only available treatment option for these conditions was another open heart surgery. Reoperation in these patients frequently carried substantially higher risk and provided a less than perfect outcome. Article see p 314 and 322 The current issue of Circulation: Cardiovascular Interventions reports two interesting series of structural intervention focusing on plugging the holes.1,2 Problems of paravalvular leak and left ventricular pseudoaneurysm are encountered infrequently, and data on transcatheter management are sketchy. Both series represent the largest reported experience in their respective areas. The reported procedural outcomes are impressive, but long-term outcomes and generalizability of these experiences remains to be tested. Although there is no obvious similarity between the two disease processes, there are several common themes for structural interventions from these reports. Paravalvular leak and ventricular pseudoaneurysm are relatively uncommon and have surgical options that are less then optimal. Percutaneous options are not well studied in the literature, and the procedures are not standardized, requiring constant procedural modifications and innovations. Appropriate patient selection requires surgical opinion and close collaboration. Procedures must be performed as a harmonious teamwork, including physical setup for “hybrid” approaches. There are no catheters or occluding devices specific to these procedures. This “orphan” status is partly due to low frequency of the disease states and partly due to the extreme variability of the target morphology. Thus tools used for the procedures should be carefully assembled from the other procedural areas, including coronary, peripheral, and structural catheterization laboratories. Procedures are performed with the guidance of advance imaging, and success is directly related to “visualization” of the anatomy. Finally, overall outcome is dependent on “successful bailout,” either surgically or with additional percutaneous procedures. Finally, for both procedures, long-term data are still awaited. Paravalvular leak is an infrequent problem that affects the mitral valve more frequently than it affects the aortic valve.3 Patients typically present with heart failure or hemolysis, but many are recognized on routine screening echocardiography. 4 Indications of paravalvular leak closure are largely similar to those with native valve regurgitation, as far as heart failure is concerned. In patients with hemolysis, severity of problem, potential risks of treatment, and likelihood of success are taken into account to determine if corrective action is necessary. Asymptomatic patients with paravalvular leak are typically monitored with periodic evaluations of functional status as well as anatomic consequences. In the present study, all but 8 patients required intervention primarily because of heart failure symptoms. Although hemolytic anemia was noted in 37% of the patients, it was not the primary reason for closure in most. Due to multiple comorbidities, it is at times difficult to determine whether symptoms are from paravalvular leak or other medical problems. Determination of chronicity and temporal relation of the paravalvular leak to symptoms can be very helpful. Patient selection process is influenced by referral process, in which only symptomatic and high-risk patients are being referred to few centers with technical expertise. Watchful waiting, surgical treatment, and percutaneous closure options should be considered individually for each patient. Technical details of the procedure, not being the focus of the study, were not highlighted in the report. Role of proper equipment selection, 3D imaging guidance, and technical challenges of the procedure should not be underestimated.