Secondary Mitral Regurgitation Flashcards
What is the estimated prevalence of mitral regurgitation (MR) in the United States?
1.7% overall; increases to 9.3% in those >75 years of age
MR is one of the most common valvular heart disorders.
How is primary mitral regurgitation classified?
Due to a structural or degenerative abnormality of the mitral valve, chordae tendineae, papillary muscles, or mitral annulus.
What characterizes secondary or functional mitral regurgitation?
Occurs in the absence of organic mitral valve disease, usually due to left ventricular dysfunction.
Is secondary MR more common than primary MR?
Yes, secondary MR is more common than primary MR.
What is the prognosis associated with secondary MR?
Worse prognosis primarily related to the severity of the underlying left ventricular dysfunction.
What structural changes can lead to secondary MR?
LV dilation due to ischemic or nonischemic cardiomyopathy can impair leaflet coaptation.
What are the two types of mitral regurgitation?
Ischemic and nonischemic.
What usually causes ischemic mitral regurgitation?
LV remodeling after myocardial infarction causing papillary muscle displacement.
What conditions can lead to nonischemic mitral regurgitation?
Hypertension or idiopathic dilated cardiomyopathy.
What is the association of secondary MR severity with clinical outcomes?
Associated with all-cause mortality and heart failure hospitalization.
What echocardiographic findings are used to classify the severity of MR?
Mild, moderate, or severe.
What is the effective regurgitant orifice area (EROA) for severe primary MR?
≥40 mm².
What is the effective regurgitant orifice area (EROA) for severe secondary MR?
≥20 mm².
What is the role of exercise echocardiography in assessing MR?
Useful when symptoms appear disproportionate to resting MR severity.
What are some predictors of failed MitraClip placement?
- Greater EROA * Baseline transmitral pressure gradient ≥4 mm².
What pharmacological treatments may help patients with LV dysfunction and secondary MR?
- Carvedilol * Metoprolol * ACE inhibitors.
What is the goal of therapy for secondary MR?
To relieve symptoms, improve quality of life, reduce HF hospitalizations, and potentially improve survival.
What is cardiac resynchronization therapy (CRT) recommended for?
Selected HF patients with LV dyssynchrony.
What effect does CRT have on secondary MR?
Overall MR severity decreases with restoration of synchronous ventricular contraction.
True or False: The predictive value of exercise echocardiography is perfect.
False.
Fill in the blank: The severity of secondary MR can vary during the _______.
cardiac cycle.
What was the sample size of the InSync Randomized Clinical Evaluation trial?
450 patients
What functional class of heart failure patients was included in the InSync trial?
NYHA functional class III/IV
What were the key outcomes of CRT in the InSync trial?
Reductions in LV end-diastolic and end-systolic volumes, improved LVEF, sustained reductions in MR
In the study of 63 HF patients with moderate to severe MR, what percentage improved by ≥1 grade?
43%
What is the association between improvement of severe secondary MR and prognosis?
Better prognosis
What percentage of patients experience improvement after CRT for severe secondary MR?
No more than one-half
What does secondary MR indicate?
It is secondary to disease of the LV, not of the valve itself
How does heart failure associated with secondary MR compare to heart failure without MR?
Worse prognosis
What does the MitraClip do?
Clips the mitral leaflets together, reducing MR
What were the findings of the Mitra-FR trial regarding MitraClip?
No reduction in repeated hospitalizations or mortality
What were the findings of the COAPT trial regarding MitraClip?
Reduced rehospitalizations and mortality in patients with severe MR and modest LV dilation
What is now FDA approved for the treatment of severe symptomatic secondary MR?
MitraClip
What is the role of guideline-directed medical therapy in patients with moderate or severe secondary MR?
Sometimes effective in reducing secondary MR and improving prognosis
What is less clear regarding treatment options for persistent severe secondary MR?
The appropriate role of surgical and transcatheter interventions
What is a key factor in making treatment decisions for secondary MR?
Accurate assessment of MR severity
True or False: Surgical approaches to secondary MR have shown improved survival compared to medical therapy.
False
Fill in the blank: The MitraClip creates a _______ orifice, reducing MR.
figure of 8
