Milrinone vs Dobutamine for the Management of Cardiogenic Shock: Implications of Renal Function and Injury.

Background: Cardiogenic shock is associated with poor clinical outcomes. There is a paucity of prospective data examining the efficacy and safety of inotropic therapy in patients with cardiogenic shock and renal dysfunction. Objectives: This study sought to examine the treatment effect of milrinone compared to dobutamine in relation to renal function. Methods: In this post hoc analysis of the DOREMI (Milrinone as Compared with Dobutamine in the Treatment of Cardiogenic Shock) trial, we examined clinical outcomes with milrinone compared to dobutamine after stratification based on baseline estimated glomerular filtration rate (eGFR) 60 ml/min/1.73 m2 and acute kidney injury (AKI). The primary outcome was the composite of in-hospital death from any cause, resuscitated cardiac arrest, receipt of a cardiac transplant or mechanical circulatory support, nonfatal myocardial infarction, transient ischemic attack or stroke, or initiation of renal replacement therapy. Results: Baseline eGFR <60 ml/min/1.73 m2 and AKI were observed in 78 (45%) and 124 (65%) of patients, respectively. The primary outcome and death from any cause occurred in 99 (52%) and 76 (40%) patients, respectively. eGFR <60 ml/min/1.73 m2 did not appear to modulate the treatment effect of milrinone compared to dobutamine. In contrast, there was a significant interaction between the treatment effect of milrinone compared to dobutamine and AKI with respect to the primary outcome (P interaction = 0.02) and death (P interaction = 0.04). The interaction was characterized by lower risk of primary outcome and death with milrinone compared to dobutamine in patients without, but not with, AKI. Conclusions: In patients requiring inotropic support for cardiogenic shock, baseline renal dysfunction and AKI are common. A modulating effect of AKI on the relative efficacy of milrinone compared to dobutamine was observed, characterized by attenuation of a potential clinical benefit with milrinone compared to dobutamine in patients who develop AKI.

Cardiorespiratory physiology, exertional symptoms, and psychological burden in post-COVID-19 fatigue.

Fatigue is a common, debilitating, and poorly understood symptom post-COVID-19. We sought to better characterize differences in those with and without post-COVID-19 fatigue using cardiopulmonary exercise testing. Despite elevated dyspnoea intensity ratings, V̇O2peak (ml/kg/min) was the only significant difference in the physiological responses to exercise (19.9 ± 7.1 fatigue vs. 24.4 ± 6.7 ml/kg/min non-fatigue, p = 0.04). Consistent with previous findings, we also observed a higher psychological burden in those with fatigue in the context of similar resting cardiopulmonary function. Our findings suggest that lower cardiorespiratory fitness and/or psychological factors may contribute to post-COVID-19 fatigue symptomology. Further research is needed for rehabilitation and symptom management following SARS-CoV-2 infection.

Clinical implications of left atrial size adjustment: Impact of obesity.

BACKGROUND: American and European societies recommend using left atrial (LA) volume adjusted to body surface area (BSA) as the means of indexing LA volume to the patient's body size irrespective of morphometric characteristics. AIM: To evaluate the impact of obesity on LA volume indexation to BSA on the presence and degree of LA enlargement. METHODS: From our echocardiography database, we extracted all consecutive adults referred for a transthoracic echocardiography in 2019 (n=28,725; 64±17 years; 55% male; 31% obese [body mass index≥30kg/m2]). LA volume indexed to BSA was calculated using measured weight (LAMeas) and ideal weight (LAIdeal) calculated using the Devine Formula. RESULTS: LAMeas and LAIdeal were 35±17mL/m2 and 40±19mL/m2, respectively (P<0.0001); 13% were classified as having a normal LAMeas but LAIdeal enlargement overall, 25% in obese patients and 7% in non-obese patients (P<0.0001). The percentages of patients with no, mild, moderate and severe LA dilatation were 57%, 19%, 9% and 16%, respectively, using LAMeas, and 45%, 20%, 11% and 24%, respectively, using LAIdeal (kappa=0.57). Degree of LA enlargement differed in 8194 patients (29%); 96% of the disagreement was related to underestimation of the degree of LA enlargement using LAMeas. Agreement for the degree of LA enlargement was poor in obese and good in non-obese patients (kappa=0.28 and 0.71, respectively). As illustrative clinical implications, diastolic function grade was modified in 8.3% of patients with preserved ejection fraction and 10.8% of patients with reduced left ventricular ejection fraction/myocardial disease, and timing for intervention was potentially different in 12.9% of patients with primary mitral regurgitation. CONCLUSIONS: Indexing LA volume to measured BSA versus ideal BSA markedly underestimates the presence and severity of LA enlargement, especially in obese patients, with potential important clinical implications.

Cardiovascular Risk Assessment in Pilots.

BACKGROUND: For over 30 yr the global medical community has attempted to define the acceptable cardiovascular risk in pilots. This challenge is compounded by the ever-changing technological and medical landscape of air travel. We aimed to review the existing literature on estimating the risk of pilot cardiovascular incapacitation and determine if the current guidelines are founded in the best available evidence.METHODS: A detailed review of the guidelines and literature that supports them was completed. Relevant articles were identified by review of the source literature of the guidelines and the references of these source documents. All articles referenced were reviewed in full by both authors. Data that informed the existing recommendations were reviewed and compared to available modern data. The results of these findings were incorporated into a formula that allows for the calculation of acceptable pilot cardiovascular risk given any operator-determined set of variables.RESULTS: Among the evidence that informs current guidelines, there exists a need for further updating. A number of assumptions have been made in creating guidelines and these may no longer reflect the current technological or medical aviation environment. Incorporating the identified variables into a formula allows for the calculation of acceptable cardiovascular risk. This formula was tested using past data and reproduced existing results.DISCUSSION: Current guidelines for pilot cardiovascular risk assessment require review by the international aviation medical community. We propose a novel formula that may serve as a template for future guidelines and may be adapted as aviation technology and health data evolve.Mulloy A, Wielgosz A. Cardiovascular risk assessment in pilots. Aerosp Med Hum Perform. 2019; 90(8):730-734.