Impact of ischaemia and scar on the therapeutic benefit derived from myocardial revascularization vs. medical therapy among patients undergoing stress-rest myocardial perfusion scintigraphy

We evaluated 1576 consecutive patients referred to MPS and stratified into 3 LV ejection fraction (LVEF) categories: ≤35%, 36-49%, and ≥ 50%. Patients with LVEF ≤35% were oldest, most often men, and with the highest likelihood of prior early (elective or urgent) coronary revascularization. They had also the highest values or summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS), as well as the highest frequency of significant coronary artery disease, and a greater number of diseased vessels. In this subgroup, 32 cardiovascular death or non-fatal myocardial infarction (MI) (21%), 35 all-cause deaths (22%), and 37 cardiovascular deaths, non-fatal MI, or late revascularizations (27%) were recorded with the shortest survival among all LVEF classes. SRS, SSS, and SDS had very low area under the curve values for the prediction of the 3 endpoints, with very high cut-offs, respectively. SRS and SSS cut-offs predicted a worse outcome in Cox regression models including the number of diseased vessels and early revascularization. In patients with LVEF ≤35%, SRS and SSS are less predictive of outcome than in patients with better preserved systolic dysfunction, but their cut-offs retain independent prognostic significance from the number of vessels with significant stenoses and from early revascularization.

In the past decade, significant advances have been made in the ability to image the heart with radionuclide tracers under stress and resting conditions in patients with suspected or known coronary artery disease (CAD) for the detection of ischemia, determination of prognosis, assessment of myocardial viability, preoperative risk assessment for patients undergoing noncardiac surgery, and evaluation of the efficacy of revascularization in patients undergoing coronary artery bypass surgery or an interventional procedure.1 For many years, planar imaging and SPECT with 201Tl constituted the only scintigraphic techniques available for detecting CAD and assessing prognosis in patients undergoing stress perfusion imaging. The major limitation of 201Tl scintigraphy is the high false-positive rate observed in many laboratories, which is attributed predominantly to image attenuation artifacts and variants of normal that are interpreted as defects consequent to a significant coronary artery stenosis. Although quantification of 201Tl images improves specificity, the false-positive rate remains problematic, particularly in women and in obese patients. Breast attenuation artifacts in women are sometimes difficult to distinguish from perfusion abnormalities secondary to inducible ischemia or myocardial scar. In recent years, new 99mTc-labeled perfusion agents have been introduced into clinical practice to enhance the specificity of SPECT and to provide additional information regarding regional and global left ventricular systolic function via ECG gating of images. It was immediately apparent that the quality of images obtained with these new 99mTc-labeled radionuclides was superior to that of images obtained with 201Tl because of the more favorable physical characteristics of 99mTc imaging with a gamma camera. With 99mTc, doses of ≈10 to 20 times higher than those that are feasible with 201Tl can be administered, yielding images with higher count density. 99mTc demonstrates less scatter and attenuation than 201Tl, which is associated …

Interhospital transfer for early revascularization in patients with ST-elevation myocardial infarction complicated by cardiogenic shock—a report from the SHould we revascularize Occluded Coronaries for cardiogenic shocK? (SHOCK) trial and registry

Extent of Myocardial Ischemia on Positron Emission Tomography and Survival Benefit With Early Revascularization

Can the reversible regional wall motion abnormalities on stress gated Tc-99m sestamibi SPECT predict a future cardiac event?

The goal of this study was to assess the clinical value of stress myocardial perfusion scintigraphy (MPS) in elderly patients (> or =75 years of age). We followed up 5200 elderly patients (41% exercise) after dual-isotope MPS over 2.8+/-1.7 years (362 cardiac deaths [CDs], 7.0%, 2.6%/y) and a subset with extended follow-up (684 patients for 6.2+/-2.9 years; 320 all-cause deaths). Survival modeling of CD revealed that both MPS-measured ischemia and fixed defect added incrementally to pre-MPS data in both adenosine and exercise stress patients. Modeling a subset with gated MPS (n=2472) revealed that ejection fraction and perfusion data added incrementally to each other, further enhancing risk stratification. Unadjusted, annualized post-normal MPS CD rate was 1.3% but <1% in patients with normal rest ECG, exercise stress, or age of 75 to 84 years and was 2.3% to 3.7% in patients > or =85 years of age or undergoing pharmacological stress. However, compared with age-matched US population CD rates (75 to 84 years of age, 1.5%; > or =85 years, 4.8%), normal MPS CD rates were approximately one-third lower than the baseline risk of US individuals (both P<0.05). Modeling of all-cause death in 684 patients with extended follow-up revealed that after risk adjustment, an interaction between early treatment and ischemia was present; increasing ischemia was associated with increasing survival with early revascularization, whereas in the setting of little or no ischemia, medical therapy had improved outcomes. Stress MPS effectively stratifies CD risk in elderly patients and may identify optimal post-MPS therapy. CD rates after normal MPS are low in all subsets in relative terms compared with the age-matched US population.

To investigate the prognostic relevance of coronary anatomy, coronary function, and early revascularization in patients with stable coronary artery disease (CAD). From March 2009 to June 2012, 430 patients with suspected CAD (61 ± 9 years, 62% men) underwent coronary anatomical imaging by computed tomography coronary angiography (CTCA) and coronary functional imaging followed by invasive coronary angiography (ICA) if at least one non-invasive test was abnormal. Obstructive CAD was documented by ICA in 119 patients and 90 were revascularized within 90 days of enrolment. Core laboratory analysis showed that 134 patients had obstructive CAD by CTCA (>50% stenosis in major coronary vessels) and 79 significant ischaemia by functional imaging [>10% left ventricular (LV) myocardium]. Over mean follow-up of 4.4 years, major adverse events (AEs) (all-cause death, non-fatal myocardial infarction, or hospital admission for unstable angina or heart failure) or AEs plus late revascularization (LR) occurred in 40 (9.3%) and 58 (13.5%) patients, respectively. Obstructive CAD at CTCA was the only independent imaging predictor of AEs [hazard ratio (HR) 3.2, 95% confidence interval (CI) 1.10-9.30; P = 0.033] and AEs plus LR (HR 4.3, 95% CI 1.56-11.81; P = 0.005). Patients with CAD in whom early revascularization was performed in the presence of ischaemia and deferred in its absence had fewer AEs, similar to patients without CAD (HR 2.0, 95% CI 0.71-5.51; P = 0.195). Obstructive CAD imaged by CTCA is an independent predictor of clinical outcome. Early management of CAD targeted to the combined anatomical and functional disease phenotype improves clinical outcome.

Background There is controversy regarding the outcome benefit from myocardial revascularization in patients with chronic coronary artery disease (CAD). We hypothesized that severely reduced regional stress myocardial blood flow (MBF) quantified by [15O]H2O positron emission tomography (PET) is associated with prognostic benefit from early revascularization. Purpose To study the interaction of regional stress MBF in absolute terms and early myocardial revascularization in predicting long-term clinical outcome in chronic CAD. Methods From pooled cohort of two academic medical centers, we identified consecutive symptomatic patients who underwent [15O]H2O PET myocardial perfusion imaging for evaluation of CAD. The lowest regional stress MBF (ml/g/min) was calculated as an average of two adjacent segments with the lowest MBF. Early revascularization was defined as percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) within 3 or 6 months after MPI (depending on the institution). Statistical interaction between stress MBF and revascularization in predicting composite endpoint of all-cause mortality, myocardial infarction (MI), and unstable angina pectoris (UAP) was analyzed by Cox regression. Hazard ratio (HR) for early revascularization was visualized across MBF values with the use of spline function. Results Out of 1600 patients (age 62 ± 9 years, 54% male), 318 (20%) underwent early revascularization (240 PCI and 78 CABG) and 228 (14%) experienced the composite endpoint during median follow-up of 7.0 years (25th–75th percentiles: 4.9–8.6 years). The cumulative incidence of the composite endpoint was higher in revascularized than non-revascularized patients (18% vs. 13%, p=0.036). There was a significant interaction (p=0.042) between the lowest regional stress MBF (adjusted HR 1.71 (95%CI 1.43-2.04) per 1 ml/g/min decrease, p&amp;lt;0.001) and effect of early revascularization (adjusted HR 0.44 (95%CI 0.21-0.93), p=0.032) on the incidence of the composite endpoint. In terms of long-term outcome, the effect of early revascularization was indifferent (i.e., HR=1) when the lowest regional MBF was approximately 2.0 ml/g/min (Figure). When the lowest regional stress MBF was less than 2.0 ml/g/min, early revascularization was associated with reduced long-term risk of the composite endpoint (HR&amp;lt;1). Conclusion In chronic CAD, early myocardial revascularization was associated with improved outcome among patients with the lowest regional stress MBF below a cut-off value of 2.0 ml/g/min by [15O]H2O PET. Quantitative severity of regional myocardial ischemia shows promise in identification of patients who gain prognostic benefit from revascularization.

Introduction Patients with moderate to severe ischemia on stress myocardial perfusion scintigraphy are at highest risk for cardiovascular adverse events and death. The presence, extent and severity of ischemia detected on myocardial perfusion scintigraphy have all decreased over the past few years. Therefore, there is an increasing need to identify patient cohorts where the results of myocardial perfusion scintigraphy will have the greatest impact on clinical management. The data on predictors of moderate to severe ischemia within contemporary population of patients are scarce. Purpose of our study was to evaluate the predictors of moderate to severe ischemia across all potentially relevant clinical parameters in a cohort of patients referred to stress myocardial perfusion scintigraphy. Methods The clinical data and myocardial perfusion scintigraphy results of 4620 consecutive patients admitted to our department from January 2020 to December 2023 were prospectively collected. All patients underwent a 2-day stress/rest 99mTc tetrofosmin (Myoview, GE Healthcare) myocardial perfusion scintigraphy. Patients were imaged in the sitting position using a Cardius® X-ACT camera (Digirad, California, USA). The magnitude of myocardial ischemia was determined semi quantitatively in a 17-segment model according to the European Association of Nuclear Medicine guidelines. Patients were categorized in moderate to severe ischemia (&amp;gt;10% ischemia) and &amp;lt;10% of ischemia groups. Results The baseline clinical characteristics of the study population according to the degree of ischemia are shown in Table 1. Of the 4620 patients, 1695 (36.7%) had ischemia, 191 (4.1% of all patients, 11% of patients with ischemia) had moderate to severe ischemia. The proportion of male gender and the frequency of diabetes, dyslipidemia and prior coronary artery disease were higher in patients with moderate to severe ischemia (all p &amp;lt;0.001, Table 1). Patients with moderate to severe ischemia had more often typical chest pain, were inpatients and had a higher frequency of myocardial scar (all p &amp;lt;0.001, Table 1). In multivariable analysis male gender, diabetes, typical chest pain, known coronary artery disease and inpatient status turned out as predictors of moderate to severe ischemia (Table 2). Dyslipidemia and myocardial scar were not significant predictors (Table 2). Conclusion The prevalence of moderate to severe ischemia is particularly high among diabetic male patients with typical chest pain and known coronary artery disease. These observations may be used in clinical practice to identify patients who are most likely to benefit from referral to stress myocardial perfusion scintigraphy.

Clinical Summaries

BackgroundWe aimed to compare the prognostic value of myocardial perfusion scintigraphy (MPS) and dobutamine stress echocardiography (DSE) in patients with end-stage renal disease (ESRD) without known coronary artery disease. MethodsTwo-hundred twenty-nine ESRD patients who applied for kidney transplantation at our centre were prospectively evaluated by MPS and DSE. The primary endpoint was a composite of myocardial infarction (MI) or all-cause mortality. The secondary endpoint included MI or coronary revascularization (CR) not triggered by MPS or DSE at baseline. ResultsMPS detected reversible ischemia in 31 patients (13.5%) and fixed perfusion defects in 13 (5.7%) patients. DSE discovered stress-induced wall motion abnormalities (WMAs) in 28 (12.2%) and at rest in 18 (7.9%) patients. MPS and DSE results agreed in 85.6% regarding reversible defects (κ = 0.358; P < .001) and in 90.8% regarding fixed defects (κ = 0.275; P < .001). Coronary angiography detected relevant stenosis > 50% in only 15 of 38 patients (39.5%) with pathological findings in MPS and/or DSE. At a median follow-up of 8 years and 10 months, the primary endpoint occurred in 70 patients (30.6%) and the secondary endpoint in 24 patients (10.5%). The adjusted Cox hazard ratios (HRs) for the primary endpoint were 1.77 (95% CI 1.02-3.08; P = .043) for perfusion defects in MPS and 1.36 (95% CI 0.78-2.37; P = ns) for WMA in DSE. The secondary endpoint was significantly correlated with the findings of both modalities, MPS (HR 3.21; 95% CI 1.35-7.61; P = .008) and DSE (HR 2.67; 95% CI 1.15-6.20; P = .022). ConclusionPerfusion defects in MPS are a stronger determinant of all-cause mortality, MI and the need for future CR compared with WMAs in DSE. Given the complementary functional information provided by MPS vs DSE, results are sometimes contradictory, which may indicate differences in the underlying pathophysiology.

Value of Electrocardiographically Gated Single-Photon Emission Computed Tomographic Myocardial Perfusion Scintigraphy in a Cohort of Symptomatic Postmenopausal Women

We assessed the prognostic value of myocardial perfusion scintigraphy (MPS) with cadmium-zinc-telluride in addition to clinical and coronary anatomy analysis. We prospectively enrolled 1464 patients (26% females, 69.5 ± 10.4 years) referred for stress-rest MPS. All the patients underwent invasive coronary angiography (1171, 80%) or coronary computed tomography angiography (293, 20%). We defined a composite endpoint of cardiovascular death and non-fatal MI. After an 8-year follow-up, summed stress score (SSS) had the highest accuracy in predicting primary endpoint with a ROC-derived cut-off of SSS >8 (>10% myocardium). SSS >8 portended the lowest survival probability at Kaplan-Meier analysis (P < 0.0001 for the composite endpoint and individual components). The Cox-regression analysis indicated SSS as an independent predictor of the composite endpoint, along with fasting blood glucose and total cholesterol and contrary to coronary anatomy parameters. Patients with SSS >8 treated with optimal medical therapy (OMT) had the largest area of necrosis, the lower ischaemic burden, the most compromised LV systo-diastolic function and the highest LV mass, but received a less aggressive treatment in comparison to early revascularized patients. Survival analysis revealed patients with SSS ≤8 had the greater freedom from events, irrespective of the treatment strategy, while the group with SSS >8 and OMT had the worst outcome, followed by patients with SSS >8 and early revascularization (log-rank test: all P < 0.0001). MPS-SSS constitutes a strong independent predictor of future adverse events after adjustment for multiple clinical parameters and coronary angiography. In particular, MPS could help risk stratification of patients who did not undergo early revascularization.

Table of ContentsI. IntroductionA. Development of GuidelinesB. General ApproachC. Preoperative Clinical EvaluationII. Further Preoperative Testing to Assess Coronary RiskA. Clinical MarkersB. Functional CapacityC. Surgery-Specific RiskIII. Management of Specific Preoperative Cardiovascular Condition

Coronary artery disease is a major cause of mortality and morbidity after renal transplant. Fragmented QRS on standard 12-lead electrocardiograms has been proposed as a marker of myocardial scar, mainly due to coronary artery disease. Here, we aimed to investigate fragmented QRS to detect severe coronary artery disease in renal transplant candidates. We retrospectively reviewed the medical records of 534 patients with end-stage renal failure who were on the deceased-donor renal transplant wait list at Başkent University Faculty of Medicine due to having no living kidney donor available. We evaluated patients with standard 12-lead electrocardiograms, myocardial perfusion scintigraphy, and coronary angiography. We compared fragmented QRS prevalence versus myocardial perfusion scintigraphy abnormalities and severe coronary artery disease. Correlations among these were analyzed. Of 92 renal transplant candidates (median age of 56.5 y; range, 24-80 y), 87 patients (94.6%) had myocardial perfusion defects and 72 (78.3%) had myocardial wall motion abnormalities on myocardial perfusion scintigraphy. Forty-four patients (47.8%) had severe coronary artery disease on coronary angiography, and 51 patients (55.4%) had fragmented QRS. Fragmented QRS was significantly more common among patients with myocardial scar. Coronary artery disease was significantly more common in patients with fragmented QRS (P = .042) and in those with fragmented QRS combined with myocardial perfusion defects (P < .01). Fragmented QRS was significantly correlated with presence of myocardial scar and any perfusion defects. When combined with myocardial perfusion defects, fragmented QRS was significantly correlated with severe coronary artery disease (P < .05). Fragmented QRS was significantly correlated with abnormal myocardial perfusion scintigraphy and severe coronary artery disease in renal transplant candidates. This simple parameter can provide valuable information on severe coronary artery disease and help to prevent excess patient morbidity and mortality from this disease after renal transplant.