Meeting News
Title: Comparative Effectiveness Of Exercise Electrocardiography Versus Exercise Electrocardiography Plus Myocardial Perfusion SPECT In Women With Suspected Coronary Artery Disease: Results From The What’s The Optimal Method For Ischemia Evaluation In Women Trial
Event: AHA 2010
Topic(s): General Cardiology, Noninvasive Cardiology
Presenter: Leslee Shaw
Writer(s): Xiushui Ren
Date Posted: 11/16/2010
Summary
In women with low-intermediate CAD likelihood and who are capable of exercising, exercise ECG testing is more cost-effective than exercise myocardial perfusion testing, with similar outcomes at two years.
Background
In women with suspected CAD, myocardial perfusion (using single photon emission computed tomography) with exercise ECG (ECG+MPS) is frequently added to exercise ECG testing (Ex ECG) because of known false positives of Ex ECG alone in this population. However, The effectiveness of Ex ECG compared to Ex ECG+MPS as a strategy for diagnosis and prognosis in women with suspected CAD is unknown.
Study Design
The What is the Optimal Method for Ischemia Evaluation in Women (WOMENs) trial is a multicenter study comparing Ex ECG to ECG+MPS in women with suspected CAD with low-intermediate CAD likelihood and who were capable of performing exercise testing. Women randomized to the Ex ECG group underwent standard or modified Bruce protocol with standard ECG criteria for ischemia. For women assigned to the ECG+MPS group, summed stress score (SSS) was calculated based on American Society of Nuclear Cardiology recommendations. ECG and MPS were interpreted at local sites.
The primary endpoint was a combination of major adverse cardiac events (MACE), which consisted of CAD death, MI, or hospital admission for unstable angina or heart failure. Events were adjudicated by an external committee blinded to randomization.
Results and Conclusions
A total of 44 centers enrolled 824 women. At baseline, the two groups were similar. The mean age was 63 years, and 78% of women were post-menopausal. The presenting symptom was chest pain in 90% of women, and dyspnea in 50%. The mean METs achieved during testing was 8.5, and 88% of women achieved at least 85% of age-predicted maximal heart rate. At least 1 mm of stress-induced ST-segment deviation occurred in 35% of women.
Exercised-related ECG results for both groups were not statistically different between the two groups, with about 65% categorized as normal, 15% equivocal, and 20% abnormal. MPS result was normal in 90% of women (in the ECG+MPS group). At 2-year follow-up, the MACE-free survival by testing group was similar (~98%). Using coronary angiography as the gold standard, Ex ECG had a sensitivity and specificity of 33% and 59%, respectively, whereas ECG+MPS had a sensitivity and specificity of 73% and 71%, respectively. Over the 2-year follow-up, 18% of women in the Ex ECG group crossed over to receive ECG+MPS, and 9% of women in the ECG+MPS group had repeat ECG+MPS, p<0.001. The median total cost of testing (including initial cost and follow-up cost) for was $174 for Ex ECG group and $493 for ECG+MPS group, p<0.001).
Thus Ex ECG and ECG+MPS had similar outcome at two years with Ex ECG being more cost-effective.
Perspective
It is important to note that, because both groups had very low event rates (MACE of 2%) over two years, the statistical power to detect potential differences is limited. In addition, this trial studied relatively low-risk women with suspected chest pain, and the results should not to be generalized to other populations such as women with higher risk or with poor functional capacity.
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Meeting News
Title: PROTECT: Benefits of Natriuretic Peptide Guided Heart Failure Therapy for Patients with Chronic Left Ventricular Systolic Dysfunction: Primary Results of the Pro-BNP Outpatient Tailored Chronic Heart Failure Therapy (PROTECT) Study
Event: AHA 2010
Topic(s): Cardiac Biomarker, General Cardiology, Heart FailureTransplant
Presenter: James Januzzi
Writer(s): Xiushui Ren
Date Posted: 11/16/2010
Summary
In patients with systolic heart failure, NT-proBNP-guided therapy was superior to standard HF therapy in reducing adverse cardiac outcomes and improving quality of life.
Background
In patients with chronic heart failure (HF), concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP) are associated with the presence and severity of HF and predict outcome.
One of several randomized trials of chronic HF patients showed that standard HF therapy plus BNP-guided therapy (not NT-proBNP) was superior to standard HF treatment alone, largely through an increase in angiotensin-converting enzyme inhibitors (ACE-I) and beta-blocker dosages. A meta-analysis of these trials confirmed the findings the BNP-guided HF therapy may be beneficial. However, it is unclear whether NT-proBNP tailor HF therapy is superior to standard HF as previous trials with heterogeneous patient populations have returned mixed results.
Study Design
This is a prospective, single-center trial of 151 patients with systolic HF. Patients were randomized to receive either standard HF therapy plus a goal to reduce NT-proBNP ≤1000 pg/mL versus standard HF therapy alone. Inclusion criteria included age of at least 21 years, LV ejection fraction ≤ 40%, NYHA class II to IV symptoms, and acute heart failure therapy within previous 6 months. Exclusion criteria included serum creatinine > 2.5 mg/dl, expected heart transplant or coronary revascularization in the next six months, severe lung disease, PCI or CABG in previous 3 months, and inoperable valve disease.
Patients were seen every three months plus additional visits if necessary.
The primary endpoint was total cardiovascular events, a combination of worsening HF, HF hospitalization, acute coronary syndrome, ventricular arrhythmia, cerebral ischemia, and cardiovascular death. Secondary endpoints included effects of NT-proBNP-guided care on quality of life (QOL) assessed with the Minnesota Living with HF Questionnaire, and cardiac structure and function.
Results and Conclusions
At baseline, the two treatment arms were similar. The mean age was 63 years, and 85% were men. The mean LV ejection fraction was 26%, and 85% of patients were NYHA class II or III. Implantable defibrillators were present in 67% of patients, and cardiac resynchronization therapy (biventricular pacemaker) was present in 40%. There was no significant difference in baseline medical therapy, with 95% use of beta-blockers, 66% ACE-inhibitor, 50% aldosterone antagonist, and 90% loop diuretics.
After a mean follow up of 10±3 months, patients in the NT-proBNP group had a reduction in total cardiovascular events as compared with standard HF group (58 versus 100 events; P =.009). Kaplan-Meier curves demonstrated significant differences in time to first event, favoring NT-proBNP guided care (P =.03). No age interaction was found. Patients in the NT-proBNP group also had greater improvements in QOL and had greater relative improvements in LV ejection fraction, LV end-systolic index, and LV end-diastolic volume index.
At follow-up, the NT-proBNP and standard HF groups had similar beta-blocker use (97% and 96%, respectively, p=0.56) and ACE-inhibitor use (56% and 46%, p=0.20). However, the NT-proBNP group had more aldosterone antagonist use (63% vs. 45%, p=0.001), less loop diuretic use (85% vs. 96%, p=0.05), and less angiotensin receptor blocker use (12% vs. 22%, p=0.05). NT-proBNP was not significantly changed over follow-up in the control group (1946 pg/ml vs. 1844 pg/ml, p=0.61), but significantly decreased in the NT-proBNP group (2344 pg/ml vs. 1125 pg/ml, p=0.01).
References
Jourdain P, Jondeau G, Funck F, et al. Plasma brain natriuretic peptide-guided therapy to improve outcome in heart failure: the STARS-BNP Multicenter Study. J Am Coll Cardiol. 2007 Apr 24;49(16):1733-9.
Porapakkham P, Porapakkham P, Zimmet H, Billah B, Krum H. B-type natriuretic peptide-guided heart failure therapy: A meta-analysis. Arch Intern Med. 2010 Mar 22;170(6):507-14.