Comparison of Outcomes Between Milrinone and Dobutamine in Patients With Cardiogenic Shock: A Meta-Analysis of Randomized Control Trials and Observational Studies.

The aim of this systematic review and meta-analysis was to compare the outcomes between milrinone and dobutamine in patients with cardiogenic shock. The search strategy involved a comprehensive exploration of electronic databases, including PubMed, EMBASE, Cochrane Library, and Scopus from the the inception of each database up to the 31st of January 2024. A combination of keywords and Medical Subject Headings (MeSH) terms was employed to identify relevant studies. The outcomes assessed in this meta-analysis included all-cause in-hospital mortality, length of intensive care unit (ICU stay), and length of hospital stay. A total of seven studies were included in this meta-analysis enrolling 3,841 patients (2,331 in the dobutamine group and 1,510 in the milrinone group). Pooled analysis showed that the risk of all-cause mortality was significantly higher in patients receiving dobutamine compared to patients receiving milrinone (relative risk (RR): 1.43, 95% confidence interval (CI): 1.02 to 2.01, p-value: 0.04). However, the length of hospital stay and length of ICU stay were not significantly different between the two groups. Limited data are available to favor the use of one inotropic agent over another. Dobutamine might lead to a shorter hospital length of stay, but there is also a risk of increased all-cause mortality. Larger randomized studies with adequate power are needed to validate these observations.

Practice guidance for stress echocardiography.

Stress echocardiography has been one of the most promising methods for the diagnosis of ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The Japanese Society of Echocardiography produced practical guidance for the implementation of stress echocardiography in 2018. At that time, stress echocardiography was not yet widely disseminated in Japan; therefore, the 2018 practical guidance for the implementation of stress echocardiography included a report on stress echocardiography and a specific protocol to promote its use at many institutions in Japan in the future. And now, an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease and heart failure with preserved ejection fraction (HFpEF) has come, which are driven by emerging trans-catheter procedures and new recommended guideline-directed medical therapy. Based on the continued evidence of stress echocardiography, the new practical guideline that describes the safe and effective methodology of stress echocardiography is now created by the Guideline Development Committee of the Japanese Society of Echocardiography and is designed to expand the use of stress echocardiography for valvular heart disease and HFpEF, as well as ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The readers are encouraged to perform stress echocardiography which will enhance the diagnosis and management of these patients.

Resting strain analysis to identify myocardial ischemia in patients with advanced chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is associated with higher incidence of cardiovascular death. Screening for coronary artery disease in asymptomatic or mildly symptomatic patients is challenging. OBJECTIVE: The aim of this study was to investigate the incremental value of resting deformation analysis in predicting positive results for myocardial ischemia during stress transthoracic echocardiography in patients with end-stage CKD. METHODS: Sixty-one patients (mean age: 62.3 ± 11.8, 65.7% men) with end-stage CKD were included in the study. Patients underwent a resting transthoracic echocardiogram and a dobutamine stress contrast echo (DSE) protocol. Positive results of DSE were defined as stress-induced left ventricular (LV) wall motion abnormalities. RESULTS: The study cohort had normal or mildly impaired systolic function: mean LV ejection fraction (EF) was 49.2% (±10.4) and mean LV global longitudinal strain (GLS) was 14.4% (±4.5). Half of our population had impaired left atrial (LA) strain: mean LA reservoir, conduit, and contractile reserve were 24.1% (±12.6), 10.6% (±5.9), and 13.6% (±9.2), respectively. DSE was positive for ischemia in 55.7%. A significant negative association with DSE results was found for LV EF, LV GLS and the conduit phase of LA strain. Both LV and LA dimensions showed positive correlation with presence of ischemia in DSE. Multivariate logistic regression analysis showed that LV GLS was independently associated with DSE (p = 0.007), after controlling for covariates, with high diagnostic accuracy. CONCLUSION: Resting LV deformation could predict positive results during DSE, thus may be useful to better identify renal patients who might benefit from coronary artery screening.

Effect of Hypotension and Dobutamine on Gastrointestinal Microcirculations of Healthy, Anesthetized Horses.

Horses undergoing abdominal exploratory surgery are at risk of hypotension and hypoperfusion. Normal mean arterial pressure is used as a surrogate for adequate tissue perfusion. However, measures of systemic circulation may not be reflective of microcirculation. This study measured the mean arterial pressure, cardiac index, lactate, and four microcirculatory indices in six healthy, anesthetized adult horses undergoing elective laparotomies. The microcirculatory parameters were measured at three different sites along the gastrointestinal tract (oral mucosa, colonic serosa, and rectal mucosa) with dark-field microscopy. All macro- and microcirculatory parameters were obtained when the horses were normotensive, hypotensive, and when normotension returned following treatment with dobutamine. Hypotension was induced with increases in inhaled isoflurane. The horses successfully induced into hypotension did not demonstrate consistent, expected changes in systemic perfusion or microvascular perfusion parameters at any of the three measured gastrointestinal sites. Normotension was successfully restored with the use of dobutamine, while the systemic perfusion and microvascular perfusion parameters remained relatively unchanged. These findings suggest that the use of mean arterial pressure to make clinical decisions regarding perfusion may or may not be accurate.

Should the Vasoactive Inotropic Score be a Determinant for Early Initiation of VA ECMO in Postcardiotomy Cardiogenic Shock?

OBJECTIVES: The authors investigated the role of early venoarterial extracorporeal membrane oxygenation (VA ECMO) implantation in patients with postcardiotomy cardiogenic shock (PCS) on mortality and morbidity when integrating vasoactive-inotropic score (VIS) and type of catecholamine support. DESIGN: A retrospective, multicenter, observational study with propensity-weight matching. SETTING: Four university-affiliated intensive care units. PARTICIPANTS: Patients with PCS in the operating room. INTERVENTIONS: Early VA ECMO support. MEASUREMENTS AND MAIN RESULTS: Of 2,742 patients screened during the study period, 424 (16%) patients were treated with inotropic drugs, and 75 (3%) patients were supported by VA ECMO in the operating room. Patients supported by VA ECMO had a higher use of vasopressor and inotropic drugs, with a higher VIS score. After propensity matching (integrating VIS and catecholamines type), mortality (56% v 20%, p < 0.001) and morbidity (cardiac, renal, transfusion) were higher in patients supported by VA ECMO than in a matched control group. CONCLUSIONS: When matching integrated the pre-ECMO VIS and the type of catecholamines, VA ECMO remained associated with high mortality and morbidity, suggesting that VIS alone should not be used as a main determinant of VA ECMO implantation.

Dobutamine Stress Cardiovascular Magnetic Resonance Derived 2-Dimension Feature Tracking Strain Analysis in Pediatric Population with Anomalous Aortic Origin of Right Coronary Artery.

Anomalous aortic origin of right coronary artery (AAORCA) is associated with myocardial ischemia and sudden cardiac arrest/death. Risk stratification remains challenging and relies upon provocative test results. This study describes the utility of dobutamine stress cardiovascular magnetic resonance (DSCMR) and potential benefit of strain analysis in children with AAORCA. All patients less than 21 years of age with AAORCA who underwent DSCMR between July 2018 and December 2022 were included. Visual wall motion abnormalities (VWMA) at rest and during protocolized increments of dobutamine infusion were assessed. Regional and global left ventricular circumferential (GCS) and radial (GRS) strain using 2-dimension Feature tracking (2D-FT) analysis (cvi42, Circle Cardiovascular Imaging Inc.) were calculated at rest and peak response. Of the total 54 DSCMR studies performed in 51 children with median age (IQR) of 13.5 (11-15) years, FT analysis was reliably performed in 52 (96%) studies. None had VWMA. The absolute change in GCS and GRS from rest to peak dobutamine stress was 4% (1-6%) and 11% (4-18%), respectively. There was no significant difference in GCS and GRS in patients with exertional symptoms vs no/non-exertional symptoms as well as between those considered to be high-risk vs low-risk anatomical features. DSCMR-derived 2D-FT strain analysis is feasible to assess myocardial deformation in children with AAORCA and may enhance this method of provocative testing. Although there were no statically significant differences in GCS and GRS values between high and low-risk subgroups, the absolute change in GCS between rest and peak stress is diminished when compared to normal adult reports.

Site-specific effects of dobutamine on cardiac conduction and refractoriness.

BACKGROUND: Isoproterenol, a non-specific beta agonist, is commonly used during electrophysiology studies (EPS). However, with the significant increase in the price of isoproterenol in 2015 and the increasing number of catheter ablations performed, the cost implications cannot be ignored. Dobutamine is a less expensive synthetic compound developed from isoproterenol with a similar mechanism to enhance cardiac conduction and shorten refractoriness, thus making it a feasible substitute with a lower cost. However, the use of dobutamine for EPS has not been well-reported in the literature. OBJECTIVE: To determine the site-specific effects of various doses of dobutamine on cardiac conduction and refractoriness and assess its safety during EPS. METHODS: From February 2020 to October 2020, 40 non-consecutive patients scheduled for elective EPS, supraventricular tachycardia, atrial fibrillation, and premature ventricular contraction ablations at a single center were consented and prospectively enrolled to assess the effect of dobutamine on the cardiac conduction system. At the end of each ablation procedure, measures of cardiac conduction and refractoriness were recorded at baseline and with incremental doses of dobutamine at 5, 10, 15, and 20 mcg/kg/min. For the primary analysis, the change per dose of dobutamine from baseline to each dosing level of dobutamine received by the patients, comparing atrioventricular node block cycle length (AVNBCL), ventricular atrial block cycle length (VABCL) and sinus cycle length (SCL), was tested using mixed-effect regression. For the secondary analysis, dobutamine dose level was tested for association with relative changes from baseline of each electrophysiologic parameter (SCL, AVNBCL, VABCL, atrioventricular node effective refractory period (AVNERP), AH, QRS, QT, QTc, atrial effective refractory period (AERP), ventricular effective refractory period (VERP), using mixed-effect regression. Changes in systolic and diastolic blood pressures were also assessed. The Holm-Bonferroni method was used to adjust for multiple testing. RESULTS: For the primary analysis there was no statistically significant change of AVNBCL and VABCL relative to SCL from baseline to each dose level of dobutamine. The SCL, AVNBCL, VABCL, AVNERP, AERP, VERP and the AH, and QT intervals all demonstrated a statistically significant decrease from baseline to at least one dose level with incremental dobutamine dosing. Two patients (5%) developed hypotension during the study and one patient (2.5%) received a vasopressor. Two patients (5%) had induced arrhythmias but otherwise no major adverse events were noted. CONCLUSION: In this study, there was no statistically significant change of AVNBCL and VABCL relative to SCL from baseline to any dose level of dobutamine. As expected, the AH and QT intervals, and the VABCL, VERP, AERP and AVNERP all significantly decreased from baseline to at least one dose level with an escalation in dobutamine dose. Dobutamine was well-tolerated and safe to use during EPS.

Prognostic value of transvalvular flow rate in patients with low-gradient severe aortic stenosis: A dobutamine stress echocardiography study.

BACKGROUNDS: There are limited data on the clinical relevance of transvalvular flow rate (Qmean ) at rest (Qrest) and at peak stress (Qstress ) during dobutamine stress echocardiography (DSE) in patients with low-gradient severe aortic stenosis (LG-SAS). METHODS: We retrospectively analyzed the clinical data of patients with LG-SAS who underwent DSE. LG-SAS was defined as an aortic valve (AV) area index of < .6 cm2 /m2 and a mean AV pressure gradient (AVPG) of < 40 mm Hg. The primary endpoint included all-cause death and heart failure hospitalization. RESULTS: Of 100 patients (mean age 79.5 ± 7.3 years; men, 45.0%; resting left ventricular ejection fraction [LVEF] 52.1% ± 15.9%; resting stroke volume index 35.8 ± 7.7 mL/m2 ; Qrest 171.8 ± 34.9 mL/s), the primary endpoint occurred in 51 patients during a median follow-up of 2.84 (interquartile range 1.01-5.21) years. When the study patients were divided into three subgroups based on Qrest and Qstress , the multivariate analysis showed that Qrest < 200 mL/s and Qstress ≥200 mL/s (hazard ratio 3.844; 95% confidence interval 1.143-12.930; p = .030), as well as Qrest and Qstress < 200 mL/s (hazard ratio 9.444; 95% confidence interval 2.420-36.850; p = .001), were significantly associated with unfavorable outcomes with Qrest and Qstress ≥200 mL/s as a reference after adjusting for resting LVEF, resting mean AVPG, chronic kidney disease, New York Heart Association functional class III/IV, and AV replacement. CONCLUSIONS: Flow conditions based on the combination of Qrest and Qstress are helpful for risk stratification in LG-SAS patients.

Safety of dobutamine or adenosine stress cardiac magnetic resonance imaging in patients with left ventricular thrombus.

BACKGROUND: Left ventricular (LV) thrombus formation is a common but potentially serious complication, typically occurring after myocardial infarction. Due to perceived high thromboembolic risk and lack of safety data, stress cardiac magnetic resonance (CMR) imaging especially with dobutamine is usually avoided despite its high diagnostic yield. This study aimed to investigate the characteristics, safety and outcome of patients with LV thrombus undergoing dobutamine or vasodilator stress CMR. METHODS: Patients undergoing stress CMR with concomitant LV thrombus were retrospectively included. Risk factors, comorbidities, and previous embolic events were recorded. Periprocedural safety was assessed for up to 48 h following the examination. Major adverse cardiac events (MACE) 12 months before the diagnosis were compared to 12 months after the exam and between patients and a matched control group. Additionally, patients were followed up for all-cause mortality. RESULTS: 95 patients (78 male, 65 ± 10.7 years) were included. Among them, 43 patients underwent dobutamine (36 high-dose, 7 low-dose) and 52 vasodilator stress CMR. Periprocedural safety was excellent with no adverse events. During a period of 24 months, 27 MACE (14.7%) occurred in patients and controls with no statistical difference between groups. During a median follow-up of 33.7 months (IQR 37.6 months), 6 deaths (6.3%) occurred. Type of stress agent, thrombus mobility, or protrusion were not correlated to embolic events or death. CONCLUSION: The addition of a stress test to a CMR exam is safe and does increase the generally high cardioembolic event rate in LV thrombus patients. Therefore, it is useful to support reperfusion decision-making.

Dobutamine use in horses during romifidine and isoflurane anaesthesia.

This retrospective study aimed to assess the incidence of hypotension and the subsequent administration of dobutamine in horses anesthetized with isoflurane and romifidine during elective surgery. Time from induction of anaesthesia to administration of dobutamine was registered, as well as the time and dose needed to restore mean arterial pressure (MAP) ≥ 70 mmHg. Additionally, the influence of patient and anaesthesia related parameters on the need for dobutamine supplementation was evaluated. In total, 118 horses were included in this retrospective study. Dobutamine was administered to effect when MAP<70 mmHg. Data registered: patient weight, acepromazine premedication, body position, administration of intraoperative ketamine bolus, locoregional anaesthesia, mechanical ventilation, duration of anaesthesia, dose and duration of dobutamine administration, heart rate, MAP before dobutamine administration, MAP and time required to increase MAP≥70 mmHg. Dobutamine infusion was needed in 54.2% of the horses 30 ± 17 min after isoflurane-romifidine anaesthesia started. Dobutamine 0.55 ± 0.18 µg kg-1 min-1 achieved a MAP≥70 mmHg in 12 ± 8 min. Duration of dobutamine infusion was 56 ± 37 min. An univariable logistic regression showed a significant association between dobutamine and acepromazine administration (p = 0.01; OR = 3.43), anaesthesia time (p = 0.02; OR = 2.41) and dorsal recumbency (p < 0.001; OR = 8.40). In a multivariable logistic regression, only dorsal recumbency significantly increased the need for dobutamine supplementation (p < 0.001; OR = 7.70). There was no significant association between patient weight (p = 0.11; OR = 1), locoregional anaesthesia (p = 0.07; OR = 0.47), administration of a ketamine bolus (p = 0.95; OR = 0.98) or volume controlled ventilation (p = 0.94; OR = 1.04) and dobutamine administration. Low doses of dobutamine were suitable to restore MAP above 70 mmHg within a limited time period. Only dorsal recumbency increased the need of dobutamine administration.

A Prospective Comparative Study between 99mTc MIBI Myocardial Perfusion Single-Photon Emission Computed Tomography and Dobutamine Stress Echocardiography to Detect Viable Myocardium in Patients with Coronary Artery Disease.

Introduction: The objective of this study was to compare 99mTc MIBI myocardial perfusion SPECT and Dobutamine Stress Echocardiography (DSE) in detecting viable myocardium in patients with Coronary Artery Disease. Materials and Methods: Total of 50 patients who with CAD and poor LV function were idenitifed on 2D Echo using 16 segment cardiac model. These patients underwent 99mTc MIBI myocardial perfusion SPECT and Dobutamine Stress Echocardiography and the results were compared with the gold standard 18F-FDG PET-CT findings. Results: A Total of 550 dysfunctional segments were identified in datasets of 50 patients on 2D echo. No significant difference was noted between the pairwise positive outcome of viable segment between MIBI SPECT and DSE (p=0.875). MIBI SPECT showed a sensitivity of 86.5% and specificity of 90.0% when compared with 18F-FDG PET-CT which was comparable with DSE having a sensitivity of 87.6% and specificity of 90.7%. Conclusion: 99mTc MIBI SPECT is an effective good alternative for evaluation of viable myocardial segments in patients with dysfunctional myocardium and can be considered especially in elderly or obese patients and patients with lung disease having poor echocardiographic imaging window due to lack of an optimal acoustic window.

Dobutamine and Goal-Directed Fluid Therapy for Improving Tissue Oxygenation in Deep Inferior Epigastric Perforator (DIEP) Flap Breast Reconstruction Surgery: Protocol for a Randomized Controlled Trial.

BACKGROUND: Breast reconstruction is an integral part of breast cancer care. There are 2 main types of breast reconstruction: alloplastic (using implants) and autologous (using the patient's own tissue). The latter creates a more natural breast mound and avoids the long-term need for surgical revision-more often associated with implant-based surgery. The deep inferior epigastric perforator (DIEP) flap is considered the gold standard approach in autologous breast reconstruction. However, complications do occur with DIEP flap surgery and can stem from poor flap tissue perfusion/oxygenation. Hence, the development of strategies to enhance flap perfusion (eg, goal-directed perioperative fluid therapy) is essential. Current perioperative fluid therapy is traditionally guided by subjective criteria, which leads to wide variations in clinical practice. OBJECTIVE: The main objective of this trial is to determine whether the use of minimally invasive cardiac output (CO) monitoring for guiding intravenous fluid administration, combined with low-dose dobutamine infusion (via a treatment algorithm), will increase tissue oxygenation in patients undergoing DIEP flap surgery. METHODS: With appropriate institutional ethics board and Health Canada approval, patients undergoing DIEP flap surgery are randomly assigned to receive CO monitoring for the guidance of intraoperative fluid therapy in addition to a low-dose dobutamine infusion (which potentially improves flap oxygenation) versus the current standard of care. The primary outcome is tissue oxygenation measured via near-infrared spectroscopy at the perfusion zone furthest from the perforator vessels 45 minutes after vascular reanastomosis of the DIEP flap. Low dose (2.5 µg/kg/hr) dobutamine infusion continues for up to 4 hours postoperatively, provided there are no associated complications (ie, persistent tachycardia). Flap oxygenation, hemodynamic parameters, and any medication-associated side effects/complications are monitored for up to 48 hours postoperatively. Complications, rehospitalizations, and patient satisfaction are also collected until 30 days postoperatively. RESULTS: Funding and regulatory approvals were obtained in 2019, but the study recruitment was interrupted by the COVID-19 pandemic. As of October 4, 2023, 34 participants have been recruited. Because of the significant delays associated with the pandemic, the expected completion date was extended. We expect the study to be completed and ready for potential news release (as appropriate) and publication by July 2024. No patients have suffered any adverse effects/complications from participating in this study, and none have been lost to follow-up. CONCLUSIONS: CO-directed fluid therapy in combination with a low-dose dobutamine infusion via a treatment algorithm has the potential to improve DIEP flap tissue oxygenation and reduce complications following DIEP flap breast reconstruction surgery. However, given that the investigators remain blinded to group randomization, no comment can be made regarding the efficacy of this intervention for improving tissue oxygenation at this time. Nevertheless, no patients have been withdrawn for safety concerns thus far, and compliance remains high. TRIAL REGISTRATION: Clinicaltrials.gov NCT04020172; https://clinicaltrials.gov/study/NCT04020172.

Prognostic value of extended cardiac risk assessment before elective open abdominal aortic surgery.

BACKGROUND: Major vascular surgery is associated with a high perioperative risk and significant mortality. Despite advances in risk stratification, monitoring, and management of perioperative complications, cardiac complications are still common. Stress echocardiography is well established in coronary artery disease diagnostics; however, its prognostic value before high-risk aortic surgery is unknown. This prospective, single-center study compared the outcome of patients undergoing extended cardiac risk assessment before open abdominal aortic surgery with the outcome of patients who had received standard preoperative assessment. METHODS: The study included patients undergoing elective open abdominal aortic surgery. Patients who underwent standard preoperative assessment before the start of a dedicated protocol were compared with patients who had extended cardiac risk assessment, including dobutamine stress echocardiography, as part of a stepwise interdisciplinary cardiovascular team approach. The combined primary endpoint was cardiovascular death, myocardial infarction, emergency coronary revascularization, and life-threatening arrhythmia within 30 days. The secondary endpoint was acute renal failure and severe bleeding. RESULTS: In total, 77 patients (mean age 68.1 ± 8.1 years, 70% male) were included: 39 underwent standard and 38 underwent cardiac risk assessment. The combined primary endpoint was reached significantly more often in patients before than after implementation of the extended cardiac stratification procedure (15% vs. 0%, p = 0.025). The combined secondary endpoint did not differ between the groups. CONCLUSIONS: Patients with extended cardiac risk assessment undergoing elective open abdominal aortic surgery had better 30-day outcomes than did those who had standard preoperative assessment.

Prevalence of cirrhotic cardiomyopathy according to different diagnostic criteria: alterations in ultrasonographic parameters of both left and right ventricles before and after stress.

Background: We estimated the frequency of cirrhotic cardiomyopathy (CCM) using all of the proposed diagnostic criteria, to describe the whole spectrum of cardiac alterations, and to investigate the role of stress in unmasking latent cases of CCM. Methods: Ninety consecutive patients were recruited. CCM was evaluated using the Montreal, the American Society of Echocardiography 2009 criteria, and the 2019 modified criteria of the CCM consortium. A dobutamine stress test was also performed. Results: Left ventricular diastolic dysfunction (LVDD) was identified in 72 (80%), 36 (40%), and 10 (11.1%) patients based on the above criteria, respectively. None of the patients had right ventricular systolic dysfunction, either at rest or after stress. The dobutamine stress test revealed left systolic dysfunction in 4 (4.5%) patients. There was agreement among the 3 criteria that the presence of LVDD was not associated with the severity of liver disease, using Child-Pugh stage. However, patients with Child-B/C had longer QTc intervals (P=0.004), higher levels of brain natriuretic peptide (P=0.016), and greater echocardiographic E/e' ratio (P<0.001) and E/e'(s) (P=0.003), compared to Child-A patients, while a significant correlation was demonstrated between Child-Pugh score and E/e' (P<0.001), or E/e'(s) (P=0.002). Conclusions: The prevalence of LVDD seems to be lower than previously considered. Right ventricular function seems to remain unimpaired. A dobutamine stress uncovered only a small percentage of patients with left systolic dysfunction. Nevertheless, the aggravation of several sonographic variables during stress, particularly in Child-B/C patients, potentially indicates a higher risk for clinical heart failure during stressful invasive interventions.

Effects of Catecholamines on Blood Flow in Preterm Infants: A Subanalysis of PICC-MBF Trial.

INTRODUCTION: This study evaluated the correlation between skin blood flow and systemic blood flow and whether skin blood flow can determine the circulatory effects of dopamine and dobutamine on blood flow in very low birth weight (VLBW) infants. METHODS: This study was a subanalysis of the PICC-MBF randomized controlled trial. The correlation between skin blood flow and echocardiographic findings was examined. Changes in skin blood flow and blood pressure before and after initiation or dose increase of dopamine and dobutamine were also evaluated. RESULTS: Two hundred and thirty-four participants underwent echocardiography. Skin blood flow was significantly correlated with supra vena cava (SVC) flow (r = 0.31, p < 0.001). Receiver operator characteristic analysis revealed that skin blood flow <17 mL/min effectively detected SVC flow <41 mL/min (area under the curve = 0.83, p < 0.001). Dobutamine significantly increased skin blood flow after initiation or dose increase (p = 0.033) without increasing blood pressure. However, dopamine significantly increased both skin blood flow (p = 0.010) and blood pressure (p < 0.001). CONCLUSIONS: Our findings indicated that skin blood flow could be used as a surrogate marker of systemic blood flow in VLBW infants and revealed differences in the effects of dopamine and dobutamine on circulation.

Safety, accuracy, and prediction of prognosis in patients with end-stage chronic kidney disease undergoing dobutamine stress cardiac magnetic resonance imaging.

Introduction: Advanced chronic kidney disease (CKD) is an independent risk factor for coronary artery disease (CAD). Due to its unique uremia-derived pathophysiology of atherosclerosis and the limitations of using potentially harmful contrast agents, the best non-invasive approach to assess CAD in these patients remains unclear. We sought to investigate the accuracy, safety, and prognosis of patients with severe CKD undergoing dobutamine stress cardiac magnetic resonance imaging (CMR). Materials and methods: In this retrospective, single-center study, patients on dialysis or with a glomerular filtration rate of <15 ml/min/1.73 m2 who underwent dobutamine stress CMR were included. A rest and stress wall motion analysis was performed using dobutamine/atropine as stressor. The target heart rate was 85% of the maximum heart rate. Periprocedural adverse events and 1-year follow-up data were obtained. Results: A total of 176 patients (127 men, 49 women) with a mean age of 60.9 ± 14.7 years were included, of which 156 patients were on permanent dialysis. Short-term symptoms such as angina or shortness of breath during stress CMR were frequent (22.1%), but major complications were rare (one patient with myocardial infarction, 0.6%). The 1-year event rate was high (16.4%) with a significant independent correlation to reduced ejection fraction at rest (p = 0.037) and failure to achieve the target heart rate (p = 0.029). The overall accuracy for predicting significant CAD was good (sensitivity of 71.4%, specificity of 98.4%) and excellent if the target heart rate was achieved (83.3%, 97.9%). A negative stress CMR was highly predictive for the absence of major adverse cardiac event or any coronary revascularization during the 1-year follow-up (negative predictive value of 95.0%). Discussion: Dobutamine stress CMR is a safe and accurate diagnostic imaging technique in patients at advanced stages of chronic kidney disease. A reduced ejection fraction and the inability to reach the target heart rate are independent predictors of a poor outcome.

Impaired vascular ß-adrenergic relaxation in spontaneously hypertensive rats: The differences between conduit and resistance arteries.

It was suggested that impaired ß-adrenergic relaxation in spontaneously hypertensive rats (SHR) might contribute to their high blood pressure (BP). Our study was focused on isoprenaline-induced dilatation of conduit femoral or resistance mesenteric arteries and on isoprenaline-induced BP reduction in SHR and Wistar-Kyoto rats (WKY). We confirmed decreased ß-adrenergic relaxation of SHR femoral arteries due to the absence of its endothelium-independent component, whereas endothelium-dependent component of ß-adrenergic smooth muscle relaxation was similar in both strains. Conversely, isoprenaline-induced relaxation of resistance mesenteric arteries was similar in both strains and this was true for endothelium-dependent and endothelium-independent components. We observed moderately reduced sensitivity of SHR mesenteric arteries to salmeterol (ß2-adrenergic agonist) and this strain difference disappeared after endothelium removal. However, there was no difference in mesenteric arteries relaxation by dobutamine (ß1-adrenergic agonist) which was independent of endothelium. The increasing isoprenaline doses elicited similar BP decrease in both rat strains, although BP sensitivity to isoprenaline was slightly decreased in SHR. The blockade of cyclooxygenase (indomethacin) and NO synthase (L-NAME) further reduced BP sensitivity to isoprenaline in SHR. On the other hand, salmeterol elicited similar BP decrease in both strains and the blockade of cyclooxygenase and NO synthase increased BP sensitivity to salmeterol in SHR as compared to WKY. In conclusion, attenuated ß-adrenergic vasodilatation of conduit arteries of SHR but similar ß-adrenergic relaxation of resistance mesenteric arteries from WKY and SHR and their similar BP response to ß-adrenergic agonists do not support major role of altered ß-adrenergic vasodilatation for high BP in genetic hypertension.

Continuous Noninvasive Blood Pressure Measurement With "ClearSight" Compared to Standard Intermittent Blood Pressure Measurement in Patients With Peripheral Arterial Disease. Are Potential Differences Influenced by Phenylephrine or Dobutamine?

OBJECTIVES: To investigate the agreement between continuous noninvasive blood pressure measurement with the ClearSight system (cNIBP-CS) and standard intermittent noninvasive blood pressure measurement (iNIBP) in patients with peripheral arterial disease (PAD). Additionally, the influence of vasoactive medication on potential measurement differences was assessed. DESIGN: A secondary analysis of a randomized controlled trial. SETTING: At a university hospital. PARTICIPANTS: Thirty-four patients with PAD undergoing percutaneous transluminal angioplasty of the lower limbs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Continuous noninvasive blood pressures were measured with the "ClearSight" system and compared to standard iNIBPs. Bland-Altman analysis revealed a mean bias of 13 mmHg (±15) between cNIBP-CS and iNIBP, with 95% limits of agreement (LOA) ranging from -17 to 42 mmHg. When comparing both medication groups, a similar mean bias was found for phenylephrine and dobutamine (12 mmHg [±13] and 13 mmHg [±13], respectively). CONCLUSION: In this study, in patients with PAD, cNIBP-CS showed an underestimation of blood pressure compared to iNIBP in phenylephrine- and dobutamine-treated patients. Compared to previous studies, a larger bias and wider 95% LOA were found.

The Utility of Low-Dose-Dobutamine Stress Echocardiography in Patients with Heart Failure with Reduced Ejection Fraction: An Update.

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF.