Comparison of long-term clinical outcomes between revascularization versus medical treatment in patients with silent myocardial ischemia.

BACKGROUND: There have been limited and conflicting results regarding the prognostic impact of revascularization treatment on the long-term clinical outcomes of silent ischemia. The current study aimed to determine whether revascularization treatment compared with medical treatment (MT) alone reduces long-term risk of cardiac death of asymptomatic patients with objective evidence of inducible myocardial ischemia. METHODS: A total of 1473 consecutive asymptomatic patients with evidence of inducible myocardial ischemia were selected from a prospective institutional registry. All patients showed at least 1 epicardial coronary stenosis with ≥50% diameter stenosis in coronary angiography. Patients were classified according to their treatment strategies. The primary outcome was cardiac death up to 10 years. RESULTS: Among the total population, 709 patients (48.1%) received revascularization treatment including percutaneous coronary intervention (PCI, n = 558) or coronary artery bypass graft surgery (CABG, n = 151), with the remaining patients (764 patients, 51.9%) receiving MT alone. During the follow-up period, the revascularization treatment group showed a significantly lower risk of cardiac death compared with the MT alone group (25.4% vs. 33.7%, HR 0.624, 95%CI 0.498-0.781, p < 0.001). Among revascularized patients, patients with negative non-invasive stress test results after revascularization showed significantly lower risk of cardiac death compared to those with residual myocardial ischemia (8.9% vs. 18.7%, HR 0.406, 95% CI 0.175-0.942, p = 0.036). CONCLUSIONS: In patients with silent myocardial ischemia, revascularization treatment was associated with significantly lower long-term risk of cardiac death compared with the MT alone group. The current results support contemporary practice of ischemia-directed revascularization, even in patients with silent myocardial ischemia.

Aminophylline and caffeine for reversal of adverse symptoms associated with regadenoson SPECT MPI.

BACKGROUND: Aminophylline shortages led us to compare intravenous (IV) aminophylline with IV and oral (PO) caffeine during routine pharmacologic stress testing with SPECT MPI. METHODS: We measured presence, duration, and reversal of adverse symptoms and cardiac events following regadenoson administration in consecutive patients randomized to IV aminophylline (100 mg administered over 30-60 seconds), IV caffeine citrate (60 mg infused over 3-5 minutes), or PO caffeine as coffee or diet cola. RESULTS: Of 241 patients, 152 (63%) received regadenoson reversal intervention. Complete (CR), predominant (PRE), or partial (PR) reversal was observed in 99%. CR by IV aminophylline (87%), IV caffeine (87%), and PO caffeine (78%) were similar (P = NS). Time to CR (162 ± 12.6 seconds, mean ± SD) was similar in treatment arms. PO caffeine was inferior to IV aminophylline for CR + PRE. CONCLUSIONS: IV aminophylline and IV caffeine provide rapid, safe reversal of regadenoson-induced adverse effects during SPECT MPI. Oral caffeine appeared similarly effective for CR but not for the combined CR + PRE. Our results suggest PO caffeine may be an effective initial strategy for reversal of regadenoson, but IV aminophylline or IV caffeine should be available to optimize symptom reversal as needed.

Impact of Appropriate Use on the Estimated Radiation Risk to Men and Women Undergoing Radionuclide Myocardial Perfusion Imaging.

UNLABELLED: The impact of appropriate use criteria (AUC) for myocardial perfusion imaging (MPI) with SPECT on the estimated lifetime attributable risk (LAR) of cancer is unknown. METHODS: A cohort of 1,511 consecutive patients who underwent clinically indicated (99m)Tc-setamibi MPI were categorized into appropriate/uncertain (n = 823) versus inappropriate (n = 688) use groups according to the 2009 AUC and were prospectively followed for 27 ± 10 mo. Logistic regression models were used to determine the annualized probability of major adverse cardiac events (MACE) of cardiac death or myocardial infarction and the probability of revascularization within 6 mo of MPI, accounting for relevant covariates. We determined LAR for each subject on the basis of accepted risk estimates. We calculated MPI's benefit-to-risk ratios, defined by the annualized predicted MACE-to-LAR ratio and the predicted 6-mo-revascularization-to-LAR ratio. RESULTS: During follow-up, there were 22 MACE and 29 6-mo revascularizations. The administered radioactivity and effective radiation doses absorbed were similar between the study groups. Patients with inappropriate MPI had significantly higher LAR (median, 0.08% vs. 0.06%, P < 0.001), lower predicted MACE-to-LAR ratio (median, 1.5 vs. 4.3, P < 0.001), and lower predicted 6-mo-revascularization-to-LAR ratio (median, 5.4 vs. 15.5, P < 0.001). Women had higher LAR (median, 0.08% vs. 0.07%, P < 0.001) and lower predicted MACE-to-LAR ratio (median, 1.9 vs. 3.3, P < 0.001) and 6-mo-revascularization-to-LAR ratio (median, 4.4 vs. 17.5, P < 0.001). However, appropriate/uncertain use negated the difference between men and women in LAR (P = 0.94) and the predicted MACE-to-LAR ratio (P = 0.97). CONCLUSION: Inappropriate MPI use is associated with excess cancer risk and lower MPI's benefit-to-risk ratio. Appropriate/uncertain use neutralizes the sex gap in LAR with MPI.

Prognostic value of automated vs visual analysis for adenosine stress myocardial perfusion SPECT in patients without prior coronary artery disease: a case-control study.

PURPOSE: We aimed to evaluate the prognostic value of automated quantitative hypoperfusion parameters derived from adenosine stress myocardial perfusion SPECT (MPS) for predicting sudden or cardiac death (CD) in case-controlled patients with suspected coronary artery disease (CAD). METHODS: We considered patients with available adenosine stress Tc-99m sestamibi MPS scans and follow-up information. 81 CD patients from a registry of 428 patients documented by the National Death Index were directly matched in a retrospective case-control design to patients without CD by key clinical parameters (age by deciles, gender, no early revascularization, pre-test likelihood categories, diabetes, and chest pain symptoms). Multivariable analysis of stress MPS total perfusion deficit (STPD) and major clinical confounders were used as predictors of CD. Visual 17-segment summed stress segmental scores (VSSS) obtained by an expert reader, were compared to STPD. RESULTS: CD patients had higher stress hypoperfusion measures compared to controls [STPD: 7.0% vs 3.6% (P < .05), VSSS: 5.3 vs 2.1 (P < .05)]. By univariate analysis, STPD and VSSS have similar predictive power (the areas under receiver operator characteristics curves: STPD = 0.64, VSSS = 0.63; Kaplan-Meier models: χ(2) = 7.59, P = .0059 for STPD and χ(2) = 11.10, P = .0009 for VSSS). The multiple Cox proportional hazards regression models with continuous perfusion measures showed that STPD had similar power to normalized VSSS as a predictor for CD (χ(2) = 4.92; P = .027) vs (χ(2) = 8.90; P = .003). CONCLUSIONS: Quantitative analysis is comparable to expert visual scoring in predicting CD in a case-controlled study.

Prognostic value of cardiac hybrid imaging integrating single-photon emission computed tomography with coronary computed tomography angiography.

Aims Although cardiac hybrid imaging, fusing single-photon emission computed tomography (SPECT) myocardial perfusion imaging with coronary computed tomography angiography (CCTA), provides important complementary diagnostic information for coronary artery disease (CAD) assessment, no prognostic data exist on the predictive value of cardiac hybrid imaging. Hence, the aim of this study was to assess the prognostic value of hybrid SPECT/CCTA images. Methods and results Of 335 consecutive patients undergoing a 1-day stress/rest (99m)Tc-tetrofosmin SPECT and a CCTA, acquired on stand-alone scanners and fused to obtain cardiac hybrid images, follow-up was obtained in 324 patients (97%). Survival free of all-cause death or non-fatal myocardial infarction (MI) and free of major adverse cardiac events (MACE: death, MI, unstable angina requiring hospitalization, coronary revascularizations) was determined using the Kaplan-Meier method for the following groups: (i) stenosis by CCTA and matching reversible SPECT defect; (ii) unmatched CCTA and SPECT finding; and (iii) normal finding by CCTA and SPECT. Cox's proportional hazard regression was used to identify independent predictors for cardiac events. At a median follow-up of 2.8 years (25th-75th percentile: 1.9-3.6), 69 MACE occurred in 47 patients, including 20 death/MI. A corresponding matched hybrid image finding was associated with a significantly higher death/MI incidence (P < 0.005) and proved to be an independent predictor for MACE. The annual death/MI rate was 6.0, 2.8, and 1.3% for patients with matched, unmatched, and normal findings. Conclusion Cardiac hybrid imaging allows risk stratification in patients with known or suspected CAD. A matched defect on hybrid image is a strong predictor of MACE.