Fractional flow reserve-guided coronary artery bypass grafting: can intraoperative physiologic imaging guide decision making?

OBJECTIVES: Fractional flow reserve-guided coronary artery bypass grafting is emerging in cardiac surgery, in which the nature (anatomic and functional characteristics) of the target vessel epicardial coronary artery stenosis is important in graft site selection. The nature of the stenosis might determine a different physiologic response to bypass grafting. We report our recent experience using near infrared fluorescence complex angiography and perfusion analysis to identify the nature of stenoses in the target vessel by imaging the physiologic response to grafting. METHODS: In 167 patients who underwent consecutive multivessel coronary artery bypass grafting cases (63% off-pump coronary artery bypass grafting) with traditional anatomy-based revascularization, we imaged and analyzed 359 grafts (53% arterial). This platform provides angiographic data of both the target vessel epicardial coronary artery and graft simultaneously (to assess the imaged competitive flow); and because a change in fluorescence intensity is proportional to the change in blood flow and perfusion, the quantified change (if any) in regional myocardial perfusion surrounding the grafted target vessel epicardial coronary artery. RESULTS: The patient outcomes in our series were excellent. All 359 grafts were widely patent by angiography, and 24% of the arterial and 22% of the saphenous vein grafts showed no regional myocardial perfusion change in response to bypass grafting. In 165 in situ internal mammary artery grafts to the left anterior descending artery (>70% stenosis), 40 had no change in regional myocardial perfusion, and 32 of the 40 had competitive flow imaged. CONCLUSIONS: An important number of angiographically patent bypass grafts demonstrated no change in regional myocardial perfusion, suggesting anatomic, but nonfunctional, stenoses in those target vessel epicardial coronary arteries. In in situ arterial grafts, imaged competitive flow is associated with nonfunctional stenoses in the target vessel epicardial coronary artery. Imaging these physiologic responses to target vessel revascularization might be useful in the emerging fractional flow reserve-guided era.

Incremental value of 111-in pentetreotide SPECT/CT fusion imaging of neuroendocrine tumors.

RATIONALE AND OBJECTIVES: Hybrid single photon-emission computed tomographic (SPECT) and computed tomographic (CT) imaging for the investigation of neuroendocrine tumors allows the fusion of functional and anatomic information in a rapid and efficient method. The aim of this study was to assess the incremental diagnostic value of (111)In pentetreotide SPECT/CT imaging compared with traditional planar and SPECT imaging with respect to lesion localization and characterization and reader confidence. MATERIALS AND METHODS: Forty-nine patients (23 male, 26 female; mean age, 56.9 years; range, 14-88 years) who underwent (111)In pentetreotide planar, SPECT, and SPECT/CT imaging were eligible for this retrospective study, including patients with suspected or confirmed carcinoid tumors (n = 24), endocrine pancreatic tumors (n = 18), medullary thyroid cancer (n = 3), paragangliomas (n = 2), and multiple endocrine neoplasia type I (n = 2). Planar and SPECT images were reviewed by two blinded readers, followed by interpretation using additional SPECT/CT images in a subsequent session. A third reader provided consensus in cases with disagreements. RESULTS: In 55 of 89 lesions (61.8%), (111)In pentetreotide SPECT/CT imaging improved lesion localization compared to planar and SPECT imaging; in 25 of 89 lesions (28.1%), SPECT/CT imaging changed lesion classification. In 20 of 49 patients (40.8%) for reader 1 and 14 of 49 patients (28.6%) for reader 2, (111)In pentetreotide SPECT/CT imaging provided incremental diagnostic value, which was considered likely to affect patient management in twelve of 20 and seven of 14 patients, respectively. Increased reader confidence was found in 32 of 49 patients (65.3%) for both readers with uniformly high confidence after SPECT/CT interpretation. CONCLUSIONS: Hybrid (111)In pentetreotide SPECT/CT imaging provides incremental diagnostic value and greater reader confidence over planar and SPECT imaging. This is achieved though superior lesion localization, the identification of physiologic activity, and additional anatomic information derived from the nondiagnostic CT portion of the study.

Incremental value of diagnostic 131I SPECT/CT fusion imaging in the evaluation of differentiated thyroid carcinoma.

OBJECTIVE: The purpose of this study was to determine the incremental value of (131)I SPECT/CT over traditional planar imaging of patients with differentiated thyroid carcinoma. MATERIALS AND METHODS: Fifty-six planar and SPECT/CT scans were obtained for 53 patients. Forty-eight scans were diagnostic (131)I studies before first radioiodine therapy, four were diagnostic (131)I studies with recombinant human thyroid-stimulating hormone stimulation, and four scans were posttherapy (131)I studies. Two nuclear physicians interpreted central neck and distant activity on planar scans and reviewed SPECT/CT images to assess the incremental diagnostic value with respect to localization and characterization of focal activity and to evaluate reader confidence. One of the readers was unblinded and had access to clinical, imaging, histologic, and biochemical information. RESULTS: Planar scans depicted 130 neck foci and 17 distant foci. At SPECT/CT these foci were further characterized as thyroglossal duct and thyroid bed remnant (n = 98), cervical nodal metastasis or local residual disease (n = 26), physiologic activity (n = 11), and distant metastasis (n = 12). Interobserver disagreement occurred on eight of 147 foci (5%). Because of superior lesion localization and additional anatomic information derived from the low-dose CT component, incremental diagnostic value with SPECT/CT over planar imaging was found for 70 of 147 foci (47.6%), including 53 of 130 neck foci (40.8%) and all 17 (100%) distant foci. Reader confidence increased regarding 104 of 147 foci (70.7%). CONCLUSION: Iodine-131 SPECT/CT is useful for accurate evaluation of regional and distant activity in characterization of foci as residual thyroid tissue or nodal, pulmonary, or osseous metastasis. Suspected physiologic mimics of disease can be confirmed with increased reader confidence.

Progression of preserved systolic function heart failure to systolic dysfunction -- a natural history study.

OBJECTIVES: To assess the natural history of left ventricular (LV) structure and function in sequential heart failure admissions with preserved systolic function. BACKGROUND: Heart failure (HF) with preserved LV systolic function accounts for between 20% and 30% of typical HF populations. Few data are available concerning the natural history of structural and functional changes in the LV in this patient population. METHODS: We consented sequential admissions from the community with confirmed heart failure to participate in this study. Doppler-echocardiography was used to assess Ejection Fraction (EF), LV structure, regional wall motion and parameters of diastolic function including E:A ratio, E-wave deceleration time (DtE) and isovolumic relaxation time (IVRT). Follow-up echocardiography was carried out at three months (mean 103+/-13 days) from discharge. RESULTS: Of 210 sequential admissions with primary heart failure 56 had preserved systolic function (LVEF> or =45%). Follow-up data at three months were available in 38 patients (mean age 72 years) with preserved LV systolic function. Of the group, 9 had been admitted within three months of discharge, 5 for recurrent HF. Eight patients (21%) exhibited significant decline in LV systolic function at follow-up, all with LVEF<45%. Three exhibited regional wall-motion abnormalities with the remainder showing dilatation and global reduction in function. None of these eight had presented to hospital for any cause other than routine outpatient department (OPD) visits during the 3 months. CONCLUSION: Patients with preserved systolic function HF, a significant number may progress to systolic dysfunction with or without clinical events.

Electronic health record systems: the vehicle for implementing performance measures.

Advances in information technology and recent national directives have the potential to support dramatic improvements in health care. Two key components are the implementation of functional electronic health record systems and widely accepted, evidence-based clinical performance measures for physicians. Midwest Heart Specialists, a 55-physician cardiovascular group at 14 locations in northern Illinois, has utilized an outpatient electronic health record system since 1997. Since 2003, the group has integrated cardiovascular measurement sets developed by the American Medical Association-convened Physician Consortium for Performance Improvement into its electronic health record system. With this integration, the group was able to capture data needed for internal quality assessment and improvement as part of routine outpatient care without the need for additional resources. Critical disease-management data for decision support are available continuously, resulting in improvements in health care. The reporting of these standardized data could be the foundation to support quality-based reimbursement strategies and physician office-based disease-management strategies.

Doppler-echocardiographic indices of diastolic function in heart failure admissions with preserved left ventricular systolic function.

Many patients admitted to hospital with heart failure have preserved left ventricular (LV) systolic function. The incidence of isolated diastolic dysfunction as a cause of such admission remains unclear. We aimed to examine diastolic function in unselected admissions from the community with heart failure using the European Study Group on Diastolic Heart Failure (ESGDHF) Doppler-echocardiographic indices of diastolic dysfunction. Primary heart failure was confirmed in 210 of 309 sequential admissions with suspected heart failure. Doppler echocardiography was used to assess left ventricular ejection fraction, wall thickness and parameters of diastolic function including E:A ratio, E-wave deceleration time and isovolumic relaxation time. Of 210 patients studied (118 female), ejection fraction was <45% in 111, leaving a population of 99 with preserved systolic function. We excluded those with significant valvular disease, leaving 56 patients (mean age=77 years) with an ejection fraction >45% and no other relevant abnormality. Twenty were in atrial fibrillation. E-wave deceleration time was >280 ms in 42%. E:A was reversed in 30 of 36 patients in sinus rhythm, but only seven met the ESGDHF criterion of E:A<0.5. Isovolumic relaxation time was >105 ms in 38%. Wall thickness was increased in 75% of cases. The ESGDHF Doppler-echocardiographic criteria for diastolic heart failure were fulfilled in 43%. In clinically confirmed heart failure, 27% of patients had preserved systolic function and no significant valvular disease. Only 43% of this group had confirmed diastolic heart failure by these ESGDHF criteria. The pathophysiological basis of the syndrome in the remaining 57% remains unclear.