Detection of Coronary Artery Disease in Women

Economic impact of contrast stress echocardiography on the diagnosis and initial treatment of patients with suspected coronary artery disease

OBJECTIVE

To estimate the impact of contrast stress echocardiography on resource use in the treatment of patients with suspected coronary artery disease (CAD).

METHODS

Fifty-nine patients with suspected CAD underwent nuclear perfusion imaging and contrast echocardiography examination. Further treatment was planned after each test and a final treatment was recommended after reviewing the results of both examinations. Medical resources and productivity losses were then collected for a 3-month follow-up period.

RESULTS

Diagnosis was possible in 96.6% of patients with nuclear perfusion imaging and 93.2% with contrast echocardiography, resulting in a cost per successful diagnosis of $637 (Can) and $476 (Can), respectively. For the majority of patients (74%), both tests provided the same result, but for 12 patients nuclear imaging suggested abnormal perfusion, whereas contrast echocardiography indicated normal function and for 2 patients it was the opposite situation. Per-patient costs for the total patient population decreased from $316 (Can) after nuclear perfusion imaging to $250 (Can) when results from both tests were known. Three-month follow-up societal costs were $441 (Can) per patient, with hospitalization contributing 58% of this total cost.

CONCLUSION

Contrast echocardiography has a similar success rate to nuclear perfusion imaging in diagnosing CAD, but has a 28% lower cost and has the potential of additional cost savings through the elimination of further diagnostic tests.

Exercise-induced myocardial ischaemia in women: factors affecting prevalence

Coronary artery disease (CAD) is a major health care challenge, and is the leading cause of death amongst women. Both the delay in the clinical manifestations of CAD and 'atypical' symptomatology in women complicates both diagnosis and treatment strategies in this population. It appears that the age-adjusted prevalence of all-cause angina (effort, unstable, etc.) appears to be greater in women than men, although stenotic lesions are demonstrated less frequently. There are a number of factors that complicates the diagnosis and identification of CAD in women, including more diffuse anginal symptoms, a lower initial detection rate of myocardial ischemia by traditional methods, lower rates of interventional procedures, and lastly, potential differences in the pathophysiology of myocardial ischemia. The lower sensitivity and specificity of many diagnostic techniques including ECG and various imaging technologies contributes significantly to these findings. The increased presence of syndrome X in post-menopausal women may reflect an increased likelihood of microcirculatory disease, where the 'gold standard' angiography fails to detect the presence of disease. Thus nonepicardial coronary stenotic disease may be largely undetected by most studies, rendering many positive ECG stress results unverifiable. The increased co-morbidity seen with CAD in women further complicates diagnosis and interventional results. Combined, these factors act to falsely lower the post-test likelihood of disease in women, adding to the existing gender bias in the diagnosis and referral rates for treatment of CAD in women. The lower precision of disease detection in women contributes to the perception that women have less exertional angina than men, despite evidence to the contrary.