The future of interventional cardiology lies in the left atrium

A tale of two pressures: a case of pseudo-prosthetic mitral valve stenosis

We present a case of an 83-year-old female with past medical history of rheumatic fever associated mitral stenosis for which she underwent mitral commissurotomy 25 years prior to presentation. Subsequently, she underwent coronary artery bypass grafting and mitral valve replacement with a bio-prosthetic valve 8 years prior to presentation. Presently, she started experiencing worsening dyspnea and heart failure symptoms. Echocardiography showed mildly reduced left ventricular ejection fraction with severe aortic stenosis and pulmonary hypertension. The bioprosthetic mitral valve was functioning normally. We performed right and left heart catheterization for evaluation. Peak aortic gradient was 50 mm Hg with a mean gradient of 39 mm Hg. Aortic valve area was calculated to be 0.31 cm(2). However, simultaneous measurement of left ventricular and wedge pressures showed a significant gradient of 11 mm Hg across the mitral valve with a calculated mitral valve area of 0.4 cm(2). Because of discordant information between echocardiographic and hemodynamic data, we proceeded with trans-septal puncture to directly measure left atrial pressures. Simultaneous left atrial and left ventricular pressure measurement demonstrated a mean gradient of 4 mm Hg across the mitral valve with an area calculated at 1.9 cm(2). We review the tracings in detail and discuss the pitfalls of using pulmonary capillary wedge pressure as a surrogate for left atrial pressure.

The role of computed tomography and magnetic resonance imaging in ablation procedures for treatment of atrial fibrillation

Cardiac ablation procedures have become the standard of therapy for various arrhythmias including atrial fibrillation. Understanding the morphological characteristics of the left atrium (LA) and pulmonary veins (PV) in detail and identification of its anatomic variants is crucial to perform a successful ablation procedure and minimize complications. The current techniques for radiofrequency ablation of atrial fibrillation include targeting the PVs or the tissue in the antrum of the LA. Localization of the anatomic structures within the LA is performed by using fluoroscopy, electroanatomic mapping, and intracardiac echocardiography. Multidimentional computed tomography and magnetic resonance angiography are invaluable techniques for better visualization of the anatomic landmarks that are essential for cardiac ablation procedures as well as prompt diagnosis and, in selected cases, prevention of procedure-related complications. Some of the complications of ablation procedures may include cardiac tamponade, PV stenosis, as well as esophageal and phrenic nerve injuries.

BioSTAR Evaluation STudy (BEST)

Background— The use of permanent synthetic implants to close atrial septal defects (ASD) and patent foramen ovale (PFO) has a number of limitations, including late complications and the limiting of transeptal access to the left heart should it be required for the later treatment of acquired heart disease. BioSTAR is a novel, bioabsorbable, atrial septal repair implant. This phase I pilot study evaluates the feasibility, safety, and effectiveness of BioSTAR for the first time in humans.

Methods and Results— We conducted a prospective, open-label, multicenter clinical study in 58 patients aged 28 to 68 years who had a clinically significant ASD or PFO. Percutaneous shunt closure was undertaken with the BioSTAR septal repair implant. Successful device implantation was achieved in 57 (98%) of 58 patients. Closure at 30 days and 6 months, assessed by contrast transthoracic echocardiography, was 48 (92%) of 52 and 54 (96%) of 56, respectively. There was no evidence of a clinically significant response to the device. Transient atrial arrhythmia occurred in 5 patients after implantation. No major safety issues were observed.

Conclusions— This study demonstrates the feasibility, safety, and effectiveness of BioSTAR for the closure of ASD and PFO in humans with a high rate of early and complete shunt closure. BioSTAR is a novel septal repair implant designed to provide biological closure of atrial-level defects using the patient’s natural healing response. Because 90% to 95% of the implant is absorbed and replaced with healthy native tissue, future access to the left atrium may be achieved.