Pioneering heart surgery of the 1960s and 70s produced revolutionary results, but at a cost to the patient in terms of extensive high-risk operations with the need for intensive care and long recovery times. In the past decade, transcatheter procedures have had a significant impact on the time needed for interventions as well as reducing hospital stays and associated costs, since patients are able to return home shortly after the procedure.
Commonly used as a means to implant stents, new technological advances mean a greater number of cardiovascular interventions can be performed in this minimally invasive manner.
Reparation and even replacement of heart valves has been a standard part of the cardiac surgeon’s repertoire for many years, but it is only recently that cath lab procedures have developed to include valve replacement. This means that these interventions are now becoming possible in high-risk and/or older patients who would have previously been excluded from this type of surgery.
Low Mortality for Transcatheter Aortic Valve Replacement (TAVR)
Medtronic, a company known for its range of innovative medical solutions for interventional cardiology, recently announced the first-year results from its study on the CoreValve Evolut R System. This next-generation valve is recapturable and self-expanding; it is currently only commercially available in the U.S.
The single-arm study, which is being carried out in 60 extreme and high-risk patients from centers in Australia, New Zealand and the United Kingdom, has shown the lowest rate of all-cause mortality (6.7%) of any TAVR study in this type of patient to date. The one-year stroke rate was also low at 3.4%.
Intervention was carried out by the transfemoral route in all but one case, despite the fact that patients with smaller vessels (down to 5.0 mm) were included . Adverse events such as valve dysfunction, annular rupture, coronary occlusion, valve thrombosis, embolisation, or conversion to surgery were correspondingly low.
Mitral Valve Replacement in a 72-year-old Patient
Mitral regurgitation (MR) is one of the most common valve disorders; however, many of the most severely affected patients are not referred for surgery because of advanced age, comorbidities or severe left ventricular dysfunction. Transcatheter mitral valve implantation may present a better therapeutic option for these high-risk patients.
The Israeli company MValve Technologies recently announced that their catheter based transapical mitral valve replacement system had been used to successfully implant a replacement mitral valve in a 72-year-old male with longstanding history of valve disease. The procedure was carried out at the University Clinic Bonn in Germany, although the patient’s general cardiac status and unfavorable mitral valve anatomy had previously ruled out surgery.
The MValve docking device provides a secure platform within the mitral annulus for implanting transcatheter heart valves—like the Lotus valve—in the native mitral position. Post-operative imaging confirmed that the valve was positioned correctly and functioning well with no residual regurgitation.
The procedure is similar in many ways to the valve-in-valve or valve-in-ring procedures that are currently performed to correct degenerated surgical prostheses.
World’s Smallest Pacemaker
Correcting cardiac arrhythmia sometimes requires implantation of a cardiac pacemaker. As with any intervention, this type of surgery also involves risks such as abnormal wound healing, vascular obliteration or inflammation around the electrode. The Micra transcatheter pacemaker, from Medtronic, functions without an electrode and is small, weighing only 1.75 grams (26 mm long and 6.7 mm in diameter).
The device is inserted via the femoral vein, and once in place, it attaches itself to the internal wall of the right ventricle via the trabeculae, the muscle fibers of the heart. The pacemaker then delivers the necessary electrical impulses to the heart wall to regulate the rhythm.
With a battery life of 10 years, instead of removing the pacemaker to change the battery, a new device is implanted next to the defunct one; the device is intended only for use in patients over the age of 70 years as only 1 or 2 implants are envisaged.
Dr. Vítor Lagarto from the Hospital Geral Santo António Porto, Portugal is an interventional cardiologist whose department is part of a network testing these small pacemakers. He has carried out a pilot study, so far placing the pacemakers in two patients. His colleague João Silveira is a specialist in heart valve replacement. Both are highly enthusiastic about these new developments. “So far we have had excellent results with these new technologies and have been able to perform operations in patients that previously would have been excluded from this type of procedure.”
Platforms such as the Corindus CorPath System are gaining certification for catheter-based procedures. FDA approval for the CorPath System was obtained based on the successful outcome of a clinical trial in 30 patients. The system can be used for percutaneous coronary interventions (PCIs) performed via the radial artery.
In the U.S., this route is used in more than 40% of interventions and is considered to deliver similar success as femoral procedures, but with fewer access site or vascular complications. Studies suggest that radial PCI procedures can significantly reduce hospital stays and associated costs as patients are able to return home shortly after intervention.