Low-dose dobutamine stress gated blood pool SPECT assessment of left ventricular contractile reserve in ischemic cardiomyopathy: a feasibility study

Abstract Purpose: The purpose of present study was to assess the feasibility of GBPS with low-dose dobutamine (LDD) stress test, performed on a SPECT camera equipped with Cadmium-Zinc-Telluride (CZT) solid state detectors in evaluation of patients with ischemic heart failure (HF).Methods. A total of 52 patients with ischemic cardiomyopathy (ICM) and a control group of 10 patients without obstructive coronary artery lesion underwent GBPS and transthoracic echocardiography (TTE) at rest and during LDD stress test (5, 10, 15 µg/kg/min). The duration of each GBPS step was 5 minutes. Stress-induced changes (∆) in LV ejection fraction (LVEF), peak ejection rate, LV volumes and dyssynchrony (phase histogram standard deviation, phase histogram bandwidth and entropy) obtained with GBPS were estimated. Results. All GBPS indices except end-diastolic volume showed significant dynamics during stress test in both groups. 17% of ICM patients, but none from control group, showed a decrease in EF during stress, accompanied by a significant increase in entropy. The inter-rater reproducibility was excellent for both rest and stress studies. There was a moderate correlation (r=0.5, p=0.01) between GBPS and TTE, with a mean difference value of -1.7 (95% confidence interval -9.8; 6.4; p=0.06) in ΔLVEF. Conclusion. Low-dose dobutamine stress gated blood pool SPECT performed with high-efficiency CZT-SPECT cameras allow evaluation of stress-induced changes in LV contractility and dyssynchrony in patients with ischemic HF. The high sensitivity of the semiconductor detectors provides an opportunity to perform GBPS with lower acquisition time and a decrease in patient radiation exposure. ClinicalTrials.gov identifier: NCT04508608 (August 7, 2020)

Download Full-text

Safety of low-dose dobutamine stress test in coronary slow flow phenomenon

Tropical Journal of Pharmaceutical Research ◽

10.4314/tjpr.v20i11.29 ◽

2021 ◽

Vol 20 (11) ◽

pp. 2443-2449

Author(s):

Jian Wu ◽

Rongchong Huang ◽

Shuang Meng ◽

Yanzong Yang

Keyword(s):

Infusion Rate ◽

Low Dose ◽

Stress Test ◽

Dobutamine Stress ◽

Control Group ◽

Slow Flow ◽

Flow Phenomenon ◽

Dobutamine Stress Test ◽

Coronary Slow Flow ◽

Coronary Slow Flow Phenomenon

Purpose: To investigate the feasibility and safety of a low-dose dobutamine stress test in coronary slow flow phenomenon (CSFP) patients.Methods: One hundred and forty-two CSFP patients, and forty-four patients without CSFP or significant epicardial coronary stenosis who served as the control group, were retrospectively reviewed. All patients were infused intravenously with dobutamine at an initial infusion rate of 5 μg/kg/min which was then increased at 8-min intervals to 10, 15, and 20 μg/kg/min. Symptoms and echocardiography were monitored simultaneously.Results: Patient tolerance decreased as the doses of dobutamine increased. No termination of the test occurred without dobutamine or at the infusion rate of 5 μg/kg/min. Nonetheless, when the infusion rates were adjusted to 15 and 20 μg/kg/min, the incident of side effects reached up to 30.9 %, and a few patients experienced ST-segment depression in precordial electrocardiographic leads. There were no induced arrhythmias without dobutamine, while the incidence of arrhythmias was highest at the infusion rate of 20 μg/kg/min. Malignant arrhythmias such as ventricular fibrillation and sustained ventricular tachycardia, were not detected. No significant differences were showed in echocardiogram result for left ventricular ejection fraction (LVEF) between CSFP and control group (63.7±7.9 in the CSFP group, versus 64.3±7.2 in the control group; p = 0.63).Conclusion: A low-dose dobutamine stress test is safe and feasible in CSFP patients.

Download Full-text

Preservation of Contractile Reserve and Diastolic Function by Inhibiting the NLRP3 Inflammasome with OLT1177® (Dapansutrile) in a Mouse Model of Severe Ischemic Cardiomyopathy Due to Non-Reperfused Anterior Wall Myocardial Infarction

Molecules ◽

10.3390/molecules26123534 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3534

Author(s):

Joseph Aliaga ◽

Aldo Bonaventura ◽

Eleonora Mezzaroma ◽

Yogesh Dhakal ◽

Adolfo Gabriele Mauro ◽

...

Keyword(s):

Myocardial Infarction ◽

Diastolic Function ◽

Nlrp3 Inflammasome ◽

Ischemic Cardiomyopathy ◽

Left Ventricular ◽

Control Group ◽

Contractile Reserve ◽

Standard Diet ◽

Group 3 ◽

Group 1

Interleukin-1β (IL-1β), a product of the NLRP3 inflammasome, modulates cardiac contractility and diastolic function. We proposed that OLT1177® (dapansutrile), a novel NLRP3 inhibitor, could preserve contractile reserve and diastolic function after myocardial infarction (MI). We used an experimental murine model of severe ischemic cardiomyopathy through the ligation of the left coronary artery without reperfusion, and after 7 days randomly assigned mice showing large anterior MI (>4 akinetic segments), increased left ventricular (LV) dimensions ([LVEDD] > 4.4 mm), and reduced function (LV ejection fraction <40%) to a diet that was enriched with OLT1177® admixed with the chow in the diet at 3.75 g/kg (Group 1 [n = 10]) or 7.5 g/kg (Group 2 [n = 9]), or a standard diet as the no-treatment control group (Group 3 [n = 10]) for 9 weeks. We measured the cardiac function and contractile reserve with an isoproterenol challenge, and the diastolic function with cardiac catheterization at 10 weeks following the MI surgery. When compared with the control (Group 3), the mice treated with OLT1177 (Group 1 and 2) showed significantly greater preservation of their contractile reserve (the percent increase in the left ventricular ejection fraction [LVEF] after the isoproterenol challenge was +33 ± 11% and +40 ± 6% vs. +9 ± 7% in the standard diet; p < 0.05 and p < 0.005 for Group 1 and 2, respectively) and of diastolic function measured as the lower left ventricular end-diastolic pressure (3.2 ± 0.5 mmHg or 4.5 ± 0.5 mmHg vs. 10.0 ± 1.6 mmHg; p < 0.005 and p < 0.009 respectively). No differences were noted between the resting LVEF of the MI groups. These effects were independent of the effects on the ventricular remodeling after MI. NLRP3 inflammasome inhibition with OLT1177® can preserve β-adrenergic responsiveness and prevent left ventricular diastolic dysfunction in a large non-reperfused anterior MI mouse model. OLT1177® could therefore be used to prevent the development of heart failure in patients with ischemic cardiomyopathy.

Download Full-text