Russert's death stirs debate of over-reliance on stress echoes
|Tim Russert’ sudden death could teach us about treating asymptomatic CAD patients. Source: Men’s News Daily|
Russert had asymptomatic coronary artery disease, a calcium score ten years ago in the mid 200s, an enlarged heart, and, depending on the source, either borderline or early diabetes. In April, Russert had a negative stress echo exam. His death has stirred a debate about the proper management and preventive imaging techniques of certain high-risk patients.
Russert’s physician, internist Michael Newman, MD, in an NBC Today interview, said that Russert, 58, continuously struggled with his weight, despite daily treadmill exercise. Many of Russert’s colleagues have commented about how rigorously he worked during the current election season, adding to his stress level.
“Unfortunately, in this country and most industrialized countries, the most common first manifestation of heart disease is sudden cardiac death,” U. Joseph Schoepf, MD, cardiothoracic radiologist and director of CT research at the Medical University of South Carolina, told Cardiovascular Business News.
Schoepf said that the management of asymptomatic high-risk CAD patients, such as Russert, requires compliance from the patient.
“Behavioral change is one of the cornerstones of the management of CAD patients—weight loss, stress reduction, regular exercise and healthy eating are key,” Schoepf said. “These are key for both primary and secondary prevention,” he added.
Schoepf indicated that any one of these behavioral factors in the wrong direction could worsen the condition of a CAD patient, regardless of their risk.
The second important cornerstone of CAD management is prescribing the the appropriate lipid lowering drugs and blood pressure medications, Schoepf said. Newman has reported that Russert took both statins and blood pressure pills.
Role of Imaging
Many people are questioning the value of stress echo, since Russert passed his exam two months ago. "Unfortunately, this is probably the most common scenario that occurs with CAD patients," Schoepf said.
Like any physiological tests, a stress echo will only become positive when arteries are significantly stenotic.
Even a catheter angiogram and SPECT imaging, which are sensitive to stenosis, most likely would not have revealed the “soft plaque” lesion that ruptured and sent emboli into Russert’s coronary arteries, eventually occluding blood flow, Schoepf said.
CT angiography, however, is one of the few noninvasive imaging modalities that can detect soft plaque. The cross-sectional nature of CT can see the atherosclerotic disease changes in the vessel wall, which may or may not be stenotic, Schoepf said.
“The only other modality that can detect that sort of plaque is intravascular ultrasound, which is rarely done because it is expensive and highly invasive with a significant rate of complications,” he said.
Coronary CTA is rarely recommended for asymptomatic CAD patients, such as Russert, because it is associated with a fairly high radiation dose, and “we do not know exactly what an eventual cost-benefit analysis will show,” Schoepf said.
While a CT scan can identify the presence of plaque, it cannot predict its vulnerability—when and if it will rupture. Current research, however, has suggested that a CT scan can determine whether the plaque is more lipid-rich and therefore, more prone to rupture—which brings the discussion back to where it started.
Lifestyle modifications and aggressive statin therapy are probably the best pathway to prevent vulnerable plaques from rupturing, Schoepf said.