Abdou Elhendy
Marshfield Clinic, USA
Title: Evaluation of coronary artery disease in hypertensive patients. Role of cardiac imaging
Biography
Biography: Abdou Elhendy
Abstract
Hypertension is a major risk factor for coronary artery disease (CAD) and its complications. Accurate non-invasive diagnosis of CAD allows identification of patients in whom aggressive medical therapy and intervention may improve outcome. Challenges in the diagnosis of CAD in hypertensive patients include baseline EKG abnormalities which impair accuracy of exercise EKG interpretation. Left ventricular hypertrophy may be associated with demand ischemia in absence of obstructive CAD. Stress echocardiography using exercise or dobutamine was shown to have good accuracy. The technique is widely available and does not entail irradiation. In addition to ischemia, left ventricular mass index predicts cardiac events. Hypertensive response during stress has been related to false positive results. Stress myocardial perfusion imaging provides good sensitivity and specificity. Some studies showed reduced specificity in patients with left ventricular hypertrophy. However, many studies demonstrated similar accuracy in patients with and without hypertension. A normal stress echocardiogram or radionuclide study is associated with low risk of cardiac death and myocardial infarction during intermediate and long term follow up. Coronary CT angiography is increasingly used in patients with intermediate probability of CAD and in those with equivocal stress test. The test has high negative predictive value to rule out CAD. Disadvantages include artifacts, irradiation and risk of contrast nephropathy. Obesity is a significant comorbid condition that may impair imaging quality of different techniques. Proper selection of imaging modality depends on various clinical parameters, availability and expertise of the center with each type of imaging.