Left ventricular transient ischemic dilation during dobutamine stress echocardiography predicts multi-vessel coronary artery disease

Relationship between transient ischemic dilatation and changes in heart rate during gated SPECT acquisition in a low-risk population without perfusion defects

OBJECTIVES

Transient ischemic dilatation (TID) in myocardial perfusion single photon emission computed tomography (SPECT) is considered a marker of poor prognosis. However, it has been suggested that some cases are due to apparent volumetric changes secondary to differences in heart rate (HR) at the time of acquisition. We assessed the correlation between transient dilatation and HR in low risk patients with no perfusion defects.

METHODS

We retrospectively analyzed patients sent for 99mTc-MIBI SPECT using a 2-day protocol. We recorded the median HR during acquisition and the HR difference (HRD) between the rest and post-stress. We obtained the medium ventricular volume, end-diastolic volume (EDV), and end-systolic volume (ESV). We included patients in which TID using medium ventricular volume (TIDMV) was ≥1.2. TID was also calculated for the EDV and ESV (TIDEDV, TIDESV). We excluded patients with known coronary artery disease, perfusion defects, various ECG disorders, positive stress test, or ESV < 10 ml.

RESULTS

From a total of 2006 patients, 63 (50 exercise, 13 dipyridamole) met the criteria for analysis (age 63.8 ± 9.7, 44 men). TIDMV was 1.29 ± 0.09 and HRD 9.8 beats per minute (BPM) (range -10 to 41). There was positive correlation between HRD and TIDMV ( r  = 0.51, P  < 0.001) and TIDEDV ( r  = 0.5, P  < 0.001), but not TIDESV ( r  = 0.23, P  = 0.07). Correlation was stronger when HRD was ≥10 BPM ( r  = 0.67, P  < 0.001).

CONCLUSION

TID without perfusion defects should be interpreted with caution in the presence of HRD ≥ 10 BPM during post-stress acquisition.

Diagnosis of cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular disease (CVD) and cardiovascular death. Identifying and monitoring cardiovascular complications and hypertension is important for managing patients with CKD or kidney failure and transplant recipients. Biomarkers of myocardial ischaemia, such as troponins and electrocardiography (ECG), have limited utility for diagnosing cardiac ischaemia in patients with advanced CKD. Dobutamine stress echocardiography, myocardial perfusion scintigraphy and dipyridamole stress testing can be used to detect coronary disease in these patients. Left ventricular hypertrophy and left ventricular dysfunction can be detected and monitored using various techniques with differing complexity and cost, including ECG, echocardiography, nuclear magnetic resonance, CT and myocardial scintigraphy. Atrial fibrillation and other major arrhythmias are common in all stages of CKD, and ambulatory heart rhythm monitoring enables precise time profiling of these disorders. Screening for cerebrovascular disease is only indicated in asymptomatic patients with autosomal dominant polycystic kidney disease. Standardized blood pressure is recommended for hypertension diagnosis and treatment monitoring and can be complemented by ambulatory blood pressure monitoring. Judicious use of these diagnostic techniques may assist clinicians in detecting the whole range of cardiovascular alterations in patients with CKD and enable timely treatment of CVD in this high-risk population.

Transient Ischemic Dilatation during Stress Echocardiography: An Additional Marker of Significant Myocardial Ischemia

AIM

Left ventricular (LV) transient ischemic dilatation (TID) is not clear how it relates to inducible myocardial ischemia during stress echocardiography (SE).

METHODS AND RESULTS

Eighty-eight SEs were examined from the site certification phase of the ISCHEMIA Trial. LV end-diastolic volume (EDV) and end-systolic volume (ESV) were measured at rest and peak stages and the percent change calculated. Moderate or greater ischemia was defined as ≥3 segments with stress-induced severe hypokinesis or akinesis. Optimum cut points in stress-induced percent EDV and ESV change that identified moderate or greater myocardial ischemia were analyzed. Analysis from percentage distribution identified a > 13% LV volume increase in EDV or a > 9% LV volume increase in ESV as the optimum cutoff points for moderate or greater ischemia. Using these definitions for TID, there were 27 (31%) with TIDESV and 12 (14%) with TIDEDV . By logistic regression analysis and receiver operating characteristic curves, the percent change in ESV had a stronger association with moderate or greater myocardial ischemia than that of EDV change. Compared to those without TIDESV , cases with TIDESV had larger extent of inducible wall-motion abnormalities, lower peak stress LVEF, and higher likelihood of moderate or grater ischemia. For moderate or greater myocardial ischemia detection, TIDESV had a sensitivity of 46%, specificity of 83%, positive predictive value of 70%, and negative predictive value of 64%.

CONCLUSION

Transient ischemic dilatation by SE is a marker of extensive myocardial ischemia and can be used as an additional marker of higher risk.

Assessment of transient ischemic dilation (TID) ratio in gated SPECT myocardial perfusion imaging (MPI) using regadenoson, a new agent for pharmacologic stress testing

BACKGROUND

Abnormal values of the transient ischemic dilation (TID) ratio are associated with severe and extensive coronary artery disease (CAD). The objective of this study was to determine the relationship between TID, determined from stress and rest ventricular volumes during regadenoson gated single-photon emission computed tomography myocardial perfusion imaging (MPI) dual isotope studies, and the extent of CAD found during coronary angiography.

METHODS

195 patients who underwent dual isotope MPI with regadenoson and cardiac angiography between March 2009 and February 2010 were analyzed. TID was calculated using commercially available software, Emory Cardiac Toolbox. Mean TID values were compared across disease types. A threshold for abnormal TID was determined by adding two standard deviations (SDs) to the mean TID of the "non-obstructive CAD" subgroup.

RESULTS

In the 195-patient group analyzed, the mean TID ratio for non-obstructive CAD (n = 104) was found to be 1.09 with a SD of 0.15. In a subgroup of patients whose angiogram was within 3 months of MPI (n = 155), the mean TIDs for non-obstructive disease (n = 81), single-vessel disease (n = 35), and multi-vessel disease (n = 39) were 1.09, 1.15, and 1.19 with SDs of 0.16, 0.19, and 0.26, respectively. Those with an abnormal TID had a crude and adjusted odds ratio of 3.4 for multi-vessel disease which was statistically significant. History of diabetes was not found to be a significant confounder, effect modifier, or mediator of the relationship between the TID and the vessel disease.

CONCLUSION

The mean TID ratio in patients with multi-vessel disease was 1.19. The threshold for an abnormal TID was 1.39 with specificity of 95% and sensitivity of 15% for determining multi-vessel CAD status. We conclude that the level of TID in gated SPECT MPI using regadenoson is associated with the degree of CAD on angiography.