Abstract

The overall global growth or expansion of cardiac surgery favors the developing countries and emerging economies. At present, it is estimated that over 2 million open-heart operations are performed annually worldwide. It is also estimated that over 10,000 cardiothoracic surgeons, in over 3,000 centers, that include specialty clinics, hospitals or institutes, be that public, private or charitable, are involved in that effort. Well over one million of these operations are performed in North America and Europe. This represents ready access or availability for less than 700 million of the 7 billion global population. An estimated backlog of 15-20 million people with heart disease are in need of corrective cardiac surgery worldwide. Whereas coronary artery disease is the dominant indication for cardiac surgery in the developed countries, rheumatic and congenital cardiac diseases continue to be more prevalent in the developing countries or emerging economies. Yet coronary artery disease and degenerative valve disease are also increasing in these countries as the global population health and lifespan improves and rises. As the social, economic, environmental, political, and demographic conditions in these countries evolve, adapt, and advance, there will be a concomitant increase in cardiac services that include prevention, awareness, diagnostic evaluation, medical management, interventional treatment, surgical procedures, rehabilitation, and early, mid-term, and long-term follow-up. Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain a serious and prevalent international concern. The global prevalence of RHD is 12-15 million, of which >2.4 million are children 5-14 years of age. The annual incidence is >300,000, and the annual mortality >350,000. Rheumatic mitral valve disease is the most common condition, especially in children. The incidence is greater in females, and <25% give a history of prior ARF. This represents 30-40% of all cardiac hospital admissions in developing countries. In sub-Saharan Africa (SSA), the echocardiogram (ECHO) in clinically silent patients detects from 7.5 to 56.6/1,000, as opposed to the <1.0 to 14/1,000 prevalence in clinically detected RHD. Regarding surgery, although open mitral valve repair has become the preferred procedure for degenerative and ischemic mitral valve problems, this procedure has not gained wide application for rheumatic disease, mainly because of complex pathology, technical difficulties, and debatable long term results, especially in children. Historically, mitral valve commissurotomy (MVC), both closed and open have been successful for rheumatic mitral stenosis, with excellent long term results. Presently, interventional percutaneous balloon valvuloplasty (PBV), when available and feasible, is the favored approach, despite higher cost than closed MVC. Open repair for rheumatic mitral regurgitation, though durable in experienced centers, has mixed long term results in children < 20 years of age. Other approaches, including valve replacement with mechanical or bioprosthetic valves, mitral Ross II procedure, mitral homografts, and leaflet extension using autologous or non-autologous pericardial substitutes, have all been described and advocated. Interventional percutaneous and trans-cardiac approaches to the mitral and aortic valves are now available in advanced centers, yet remain in the clinical investigative phases. Access for testing, monitoring, and regulation of anticoagulation in low and middle income populations remains a formidable challenge, as does appropriate surgical considerations and options in child-bearing females. The decreased growth potential and reduced durability of bioprosthetic valves in young patients, with attendant cost and need for reoperation, are also major considerations. The present part 2 review in a 5 part series highlights current medical and interventional treatment of predominate rheumatic mitral valve stenosis.

Key Words

Acute Rheumatic Fever, Rheumatic Heart Disease, Mitral commissurotomy, Percutaneous balloon valvotomy, valve surgery, valve repair