Buccal caffeine strips for reversal of adverse symptoms of vasodilator stress.

BACKGROUND: Due to recurrent shortages of aminophylline, intravenous caffeine has emerged as a commonly used, safe and reliable method to treat adverse effects of vasodilator stress agents. We sought to evaluate the safety and effectiveness of buccal caffeine strips which are rapidly absorbed, inexpensive, readily available, and simplify caffeine administration. METHODS: Consecutive patients undergoing regadenoson stress SPECT MPI were assessed for the occurrence of symptoms during testing over an 11-week period at a single metropolitan hospital. Adverse symptoms, including their severity and duration, were recorded at the time of testing. Patient satisfaction was rated on a scale of 1 to 5 (5 being the most satisfied). Patients received reversal with caffeine if symptoms were felt to be significant enough by the patient and physician performing the test. The treatment received alternated week to week between IV caffeine (60 mg) or 100 mg buccal caffeine strips. Caffeine was given at least 3 minutes after tracer injection. A rescue dose of IV caffeine was offered 10 minutes later if indicated. RESULTS: Of the 122 patients enrolled in the study, 70 (57%) were included during buccal caffeine weeks and 52 (43%) during IV caffeine weeks, and only 28 (24%) received reversal with a caffeine agent. Seven (6%) received IV caffeine and 21 (17%) received buccal caffeine. There was no significant difference in symptom duration between IV and buccal caffeine after treatment (152.8 vs 163.4 seconds, P = 0.87). There was no significant difference in initial and final symptom severity between groups. Only 2 patients in the buccal group required rescue IV caffeine for ongoing symptoms and emesis. None of the IV group required a rescue dose. There was no significant difference in patient satisfaction between the groups (2.8 vs 3.2, P = 0.38). CONCLUSION: Buccal caffeine strips are a safe, well tolerated, and effective initial strategy to reverse adverse effects of vasodilator stress in the minority of patients who request it. Buccal caffeine alone or with IV rescue caffeine was highly effective in reversing adverse effects and was free of major adverse clinical events.

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.

Quantitative high-efficiency cadmium-zinc-telluride SPECT with dedicated parallel-hole collimation system in obese patients: results of a multi-center study.

BACKGROUND: Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride parallel-hole SPECT MPI for coronary artery disease (CAD) in obese patients. METHODS AND RESULTS: 118 consecutive obese patients at three centers (BMI 43.6 ± 8.9 kg·m(-2), range 35-79.7 kg·m(-2)) had upright/supine HE-SPECT and invasive coronary angiography > 6 months (n = 67) or low likelihood of CAD (n = 51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD), and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5 = excellent; < 3 nondiagnostic) was compared among BMI 35-39.9 (n = 58), 40-44.9 (n = 24) and ≥45 (n = 36) groups. ROC curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P = .02). C-TPD normalcy rate was higher than U-TPD (88% vs 75%, P = .02). Mean IQ was similar among BMI 35-39.9, 40-44.9 and ≥45 groups [4.6 vs 4.4 vs 4.5, respectively (P = .6)]. No patient had a nondiagnostic stress scan. CONCLUSIONS: In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions.

A Resident-Authored, Case-Based Electrocardiogram Email Curriculum for Internal Medicine Residents.

Introduction: The interpretation of electrocardiograms (ECGs) is a critical competency for internal medicine trainees, yet time and resources to foster proficiency are limited. Methods: This resident-authored ECG email curriculum for first-year residents involved 129 first-year internal medicine residents at three major academic university hospitals. Residents either received the resident-authored ECG email curriculum (intervention group) or continued standard training (control group). The curriculum involved 10 multiple-choice ECG cases emailed biweekly over the 6-month study period. All participants were asked to complete a pre- and postintervention test to assess ECG interpretation competency and attitudes. The primary outcome was improvement in ECG test performance. Results: Among the 129 first-year residents participating, 21 of the 65 (32%) randomized to the intervention group and 13 of the 64 (20%) randomized to the control group completed both the pre- and posttests for analysis. While all participants' ECG test scores improved over the study period (p < .001), improvement did not differ between groups (p = .860). We found that the effect of the intervention on ECG test performance varied significantly by the number of cardiology rotations an intern experienced (p = .031), benefiting naïve learners the most. All intervention group participants who completed the posttest reported they would recommend it to a colleague. Discussion: While it did not improve resident performance on an ECG posttest, this resident-authored ECG email curriculum offers a scalable way to provide trainees additional practice with ECG interpretation, with particular benefit to trainees who have not yet rotated on cardiology.