In the last two weeks, I have discussed the two most common valvular problems that we cardiologists see—AS and MR. This week I’ll give a quick overview of the other valvular problems that we can encounter.
First of all, the aortic valve can also develop regurgitation. Called “AR,” aortic regurgitation, when severe, can lead to heart enlargement, shortness of breath, chest pain, and eventually congestive heart failure. It can develop due to the abnormal thickening that causes AS, but other causes include infection, congenital (bicuspid aortic valve), and structural abnormalities of the aortic root (the part of the aorta that is immediately adjacent to the aortic valve). Ultimately, symptomatic severe AR requires surgery, though researchers continue to work on utilizing TAVR (see blog from October 30) for this condition. Because AR doesn’t necessarily lead to calcification of the aortic apparatus, the standard TAVR valve that is used for AS can’t “anchor” into the aorta—hence the need for something a little different.
The mitral valve can also become stenotic. In decades past, the primary cause of this was the late effects of rheumatic fever. However, as this infection has become much less common, mitral stenosis (MS) is more often due to progressive calcification of the mitral valve apparatus (meaning the valve and all its supporting structures, including the annulus, chordae and papillary muscles). Rheumatic MS can respond well to a catheter procedure called balloon valvuloplasty, where a balloon is inflated across the valve, separating the leaflets and enlarging the opening. However, this is not effective in highly calcified valves, so in that situation severe MS usually requires surgical replacement of the valve.
On the right side of the heart are the tricuspid and pulmonic valves. I’ll set aside the pulmonic valve quickly by saying that serious disorders of this valve—either stenosis or regurgitation—are extremely rare in adults. Generally, they are seen in infants and children with congenital heart disease or in adults who have had repaired congenital heart defects. In my 25+ years as a cardiologist, I’ve seen only 2 people who have had severe pulmonic regurgitation (PR) and 2 with severe pulmonic stenosis (PS). Even with that, they have not needed surgery.
The tricuspid valve is another story, though. It is sometimes referred to as the “forgotten” valve, in that it is often not recognized as causing a problem. While tricuspid stenosis (TS) is rare in adults, tricuspid regurgitation (TR) is common and can lead to what we call right-sided heart failure, manifested as generalized fatigue, edema of the legs, and abdominal bloating, due to fluid accumulating in the body. It can be due to a primary problem with the valve or can be secondary to pulmonary hypertension (high blood pressure in the lung circulation). The increased pressures that the right ventricle pumps against produce backward pressure against the tricuspid valve and enlargement of the tricuspid annulus, pulling the valve leaflets apart so that they don’t come together all the way. Pulmonary hypertension itself can be a primary problem, can be secondary to disorders within the lungs, or can develop due to left-sided heart failure (often due to severe MR), as the increased pressures in the left heart are transmitted passively backward into the lungs.
Again, surgery is often necessary to correct TR, though the “fix” is usually a repair with a ring placed in the tricuspid annulus, rather than complete replacement of the valve. This type of surgery is probably underutilized, partly because patients with severe TR are often very sick and at higher risk for surgery, but also because it is often assumed that when severe TR is caused by left-sided heart failure from severe MR, fixing the MR will fix the TR. Increasingly we are realizing that this is not necessarily the case.
Trials are currently underway investigating less invasive, catheter-based methods to correct severe TR. Pima Heart & Vascular is participating in one of these studies. So, stay tuned—and let me know if you or a friend or loved one has severe TR!
Greg Koshkarian, MD, FACC