SNOWMASS, COLO. – Differentiating constrictive pericarditis from restrictive cardiomyopathy in patients with right heart failure with a normal ejection fraction is “one of the most difficult diagnostic challenges in cardiology today,” but reliable results can be achieved using a careful step-by-step approach, Dr. Rick A. Nishimura said at the Annual Cardiovascular Conference at Snowmass.
Under current terminology for heart failure, cardiologists speak of HFrEF, or heart failure with reduced ejection fraction, and HFpEF, or heart failure with preserved ejection fraction. But there is a third group of patients who are often mistakenly thought to have HFpEF: those with severe right heart failure and a normal ejection fraction, classically caused by constrictive pericarditis or restrictive cardiomyopathy.
Dr. Rick A. Nishimura
Unlike patients with HFpEF, these people are not hypertensive and they don’t have pulmonary congestion. Instead, they present predominantly with ascites, peripheral edema, fatigue, and marked elevation in jugular venous pressure, noted Dr. Nishimura, professor of medicine at the Mayo Clinic in Rochester, Minn.
Before elaborating on his own tried-and-true, step-by-step approach, he highlighted several diagnostic procedures he considers less than reliable. One is advanced imaging with CT or MRI looking for the pericardial thickening that is widely viewed as an anatomic hallmark of constrictive pericarditis.
“Remember, 22% of patients with proven constrictive pericarditis actually have a normal pericardium on CT or MRI, because it’s their fibrotic epicardium that’s causing the constrictive pericarditis. And roughly 70% of patients are going to have some thickened pericardium after radiation therapy or coronary artery bypass graft surgery without having constrictive pericarditis. So CT and MRI are helpful, but they’re not going to be diagnostic,” according to the cardiologist.
Similarly, while it’s often been said that constrictive pericarditis can be diagnosed based upon a classic trio of hemodynamic findings obtained through heart catheterization – namely, early rapid filling with a left ventricular end-diastolic pressure equal to the right ventricular end-diastolic pressure, a right ventricular end-diastolic pressure greater than one-third of the right ventricular systolic pressure, and a pulmonary artery pressure below 50 mm Hg – these criteria didn’t reliably separate the last 100 patients who came to the catheterization lab at the Mayo Clinic with either constrictive pericarditis or restrictive cardiomyopathy, he continued.