Prognostic impact of thyroid stimulating hormone levels in patients with cardiomyopathy.

BACKGROUND: Thyroid stimulating hormone (TSH) abnormalities have been associated with various cardiac arrhythmias. Effect of TSH abnormalities on mortality and implantable cardioverter defibrillators (ICD) behavior in patients with cardiomyopathy has not been investigated. METHODS: Our ICD database includes 1,445 patients between December 1997 and January 2008. TSH levels using the ultra sensitive assay were available in 371 patients. Patients were classified based on TSH levels as: High TSH (N = 102, TSH > 5) and Low TSH (N = 26, TSH < 0.4). TSH groups were compared for mortality, appropriate and inappropriate ICD therapies. RESULTS: A high or low TSH was an independent predictor of all-cause mortality: Hazard ratio (HR) 1.46 (95% CI 1.03-2.08), P = 0.033 and HR 1.76 (95% confidence interval 1.02-3.03), P = 0.043 respectively. TSH abnormalities were not associated with an increased incidence in appropriate or inappropriate ICD therapy. CONCLUSION: A low or high TSH was associated with a higher mortality; however, neither were associated with appropriate or inappropriate ICD therapy after multivariate analysis. Univariate analysis demonstrated an association of high TSH and appropriate ICD therapy. However, multivariate analysis did not show this association. Therefore, we are concluding that TSH levels are predictors of all-cause mortality but not ICD therapy.

Risk stratification of CAD with SPECT-MPI in women with known estrogen status.

OBJECTIVE: To compare exercise tolerance testing (ETT) with gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) risk stratification in women with an intermediate to high CAD pretest risk and known estrogen status (ES). BACKGROUND: SPECT-MPI is an effective test for risk stratifying patients with stable angina. However in women, the current guidelines recommend the exercise tolerance testing (ETT) as first line test. Further, the relationship of stress imaging to ES, an independent risk indicator for CAD, is unknown. METHODS: 2,194 women with an intermediate to high CAD pre-test risk were referred for a clinically indicated ETT with gated SPECT-MPI. Duke treadmill scores (DTS) and summed stress score (SSS) were calculated. SSS were classified as normal (SSS < 3), mildly abnormal (SSS 4-8), or moderate-severely abnormal (SSS > 8). The ES was assessed as premenopausal, postmenopausal on hormone replacement therapy (HRT) as ES+ while postmenopausal not on HRT were ES-. An annualized cardiac event rate of a composite of cardiac death, unstable angina (UA) leading to hospitalization, non-fatal myocardial infarction, or late coronary revascularization was calculated for all the groups. RESULTS: The annualized cardiac event rate was 1.3% PPY, 2.1% PPY, and 3.2% PPY for low, intermediate, and high risk DTS (P = .2). Patients with intermediate DTS and mildly abnormal or moderate-severely abnormal gated SPECT-MPI had a significantly higher cardiac event rates (5.3% PPY and 10.8% PPY, respectively) than those with a normal gated SPECT-MPI (1.2%, PPY, P = .01). This was also demonstrated on further Cox-regression analysis. Risk stratification of SPECT-MPI over DTS was independent of ES. CONCLUSION: Gated SPECT-MPI provides risk stratification beyond standard exercise stress testing for women with suspected coronary artery disease, especially in patients with intermediate DTS and is independent of ES.

Usefulness of stress gated technetium-99m single photon emission computed tomographic myocardial perfusion imaging for the prediction of cardiac death in patients with moderate to severe left ventricular systolic dysfunction and suspected coronary artery disease.

Although stress gated technetium-99m single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) is useful in differentiating ischemic from nonischemic cardiomyopathy, its prognostic usefulness in this patient population is not well understood. Consecutive unique patients with suspected coronary artery disease who, for clinical indications, underwent technetium-99m rest and stress MPI demonstrating ejection fractions ≤40% by gated SPECT imaging were retrospectively identified. In addition to prescan variables, previously defined cutoffs for gated SPECT parameters using visual and standard 17-segment semiquantitative scoring were applied and related to the occurrence of cardiac death up to 5 years after MPI. Of the 475 patients fulfilling criteria for study inclusion, follow-up was complete in 444 (93%) over 3.7 ± 1.6 years. Of 393 patients without subsequent early (≤60 days) coronary revascularization, cardiac death occurred in 64 (16%). The summed stress score, an MPI measure of the extent and severity of coronary artery disease that also accounts for the ischemic burden, was the gated SPECT parameter most related to cardiac death with Kaplan-Meier 5-year cardiac death-free survival of 85.6% and 67.3% in patients with summed stress scores ≤8 and >8, respectively (p <0.001). In multivariate Cox regression analysis, a summed stress score >8 independently contributed to cardiac death (adjusted hazard ratio 2.20, 95% confidence interval 1.34 to 3.61), and its addition to the model significantly increased the global chi-square value over prescan variables (from 32.46 to 41.67, p = 0.002). In conclusion, stress MPI data from gated technetium-99m SPECT scans are useful for the prediction of cardiac death in patients with moderate to severe left ventricular systolic dysfunction in whom there is suspicion of underlying coronary artery disease.

Electrocardiographic changes during vasodilator SPECT myocardial perfusion imaging: does it affect diagnosis or prognosis?

BACKGROUND: Significance of electrocardiographic (ECG) changes during vasodilator stress myocardial perfusion imaging (MPI) is controversial. We examined the diagnostic and prognostic significance of ECG changes during vasodilator single photon emission computerized tomography (SPECT) MPI. METHODS: We studied consecutive patients who underwent vasodilator SPECT MPI from 1995 to 2009. Patients with baseline ECG abnormalities, previous history of coronary artery bypass graft surgery or myocardial infarction (MI) were excluded. Significant coronary artery disease (CAD) was defined as >70% stenosis of any vessel or ≥50% stenosis of left main. Mean follow-up was 2.4 ± 1.5 years for cardiac events (cardiac death and non-fatal MI). RESULTS: Of patients in the diagnostic cohort, ST depression was associated with increased incidence of CAD with abnormal (P = .020 and P <.001) but not in those with normal perfusion (P = .342). Of 3,566 patients with follow-up in the prognostic cohort, including 130 (5.0%) with ST depression and normal perfusion, the presence of ST depression ≥1 mm did not affect the outcomes in any summed stress score category. CONCLUSIONS: ST depression ≥1 mm during vasodilator SPECT MPI is associated with CAD in patients with abnormal perfusion, but provides no additional risk stratification beyond concomitant perfusion imaging, including those with normal studies.

Initial experience with a transcatheter septal closure system for secondary stroke prevention in patients with interatrial septal defects.

BACKGROUND: Percutaneous transcatheter closure of a patent foramen ovale (PFO) has been utilized over the last several years to prevent thromboembolic events in selected patients with a prior cryptogenic stroke. We describe our initial experience at Hartford Hospital with a transcatheter PFO closure system and our multidisciplinary approach. METHODS: From March to November 2002, we performed percutaneous transcatheter closure of a PFO in 16 patients with a prior history of cryptogenic stroke(s) and/or transient ischemic attack using the CardioSEAL Septal Occluder system. All 16 patients had a PFO visualized on their transesophageal echocardiogram (TEE) study, and 15 patients also had an atrial septal aneurysm. PFO closure was performed with a CardioSEAL Septal Occluder in the cardiac catheterization laboratory under general anesthesia with TEE guidance. Following device placement, all patients were discharged on a regimen of aspirin and clopidigrel, with follow-up in the Stroke Clinic. RESULTS: Successful deployment of the septal occluder and effective PFO closure was achieved in all 16 patients with no major procedural or in-hospital complications. Short-term clinical follow-up has demonstrated no recurrent neurologic thromboembolic events, but one patient was rehospitalized for de novo atrial fibrillation. Follow-up transthoracic echocardiographic assessment at three to six months postprocedure, obtained in eight patients thus far, has demonstrated no residual interatrial shunting. CONCLUSION: Our early results suggest that percutaneous PFO closure with the CardioSEAL Septal Occluder system is a safe option for secondary stroke prevention in carefully selected patients with interatrial septal defects and a history of cryptogenic stroke or TIA. Patient selection and the long-term effectiveness and safety of this approach require further assessment.