Significant prognostic impact of improvement in ventriculo-arterial coupling induced by dobutamine stress on cardiovascular outcome for patients with dilated cardiomyopathy

Prognostic Value of Ventricular-Arterial Coupling After Transcatheter Aortic Valve Replacement on Midterm Clinical Outcomes

Background

Ventricular‐arterial coupling predicts outcomes in patients with heart failure. The arterial elastance to end‐systolic elastance ratio (Ea/Ees) is a noninvasively assessed index that reflects ventricular‐arterial coupling. We aimed to determine the prognostic value of ventricular‐arterial coupling assessed through Ea/Ees after transcatheter aortic valve replacement to predict clinical events.

Methods and Results

We retrieved data on 1378 patients (70% women) who underwent transcatheter aortic valve replacement between October 2013 and May 2017 from the OCEAN‐TAVI (Optimized transCathEter vAlvular iNtervention) Japanese multicenter registry. We determined the association between Ea/Ees and the composite end point of hospitalization for heart failure and cardiovascular death by classifying the patients into quartiles based on Ea/Ees values (group 1: <0.326; group 2: 0.326–0.453; group 3: 0.453–0.666; and group 4: >0.666) during the midterm follow‐up after transcatheter aortic valve replacement. During a median follow‐up period of 736 days (interquartile range, 414–956), there were 247 (17.9%) all‐cause deaths, 89 (6.5%) cardiovascular deaths, 130 (9.4%) hospitalizations for heart failure, and 199 (14.4%) composite events of hospitalization for heart failure and cardiovascular death. The incidence of the composite end point was significantly higher in group 2 (hazard ratio [HR], 1.76; 95% CI, 1.08–2.87 [P=0.024]), group 3 (HR, 2.43; 95% CI, 1.53–3.86 [P<0.001]), and group 4 (HR, 2.89; 95% CI, 1.83–4.57 [P<0.001]) than that in group 1. On adjusted multivariable Cox analysis, Ea/Ees was significantly associated with composite events (HR, 1.47 per 1‐unit increase; 95% CI, 1.08–2.01 [P=0.015]).

Conclusions

These findings suggest that a higher Ea/Ees at discharge after transcatheter aortic valve replacement is associated with adverse clinical outcomes during midterm follow‐up.

Registration

URL: https://www.upload.umin.ac.jp/. Unique identifier: UMIN000020423.

Easy-to-use preload stress echocardiography by using combined dynamic postural stress can identify high-risk patients with heart failure with reduced ejection fraction

Aims

Haemodynamic assessment during stress testing is not commonly performed in patients with heart failure with reduced ejection fraction (HFrEF) because of its invasiveness, lower feasibility, and safety concerns. This study aimed to assess the haemodynamic characteristics of patients with HFrEF in response to non‐invasive preload stress during dynamic postural alterations achieved by combining both semi‐sitting position and passive leg‐lifting and to evaluate whether combined postural stress could be used for risk stratification in these patients.

Methods and results

For this study, 101 patients with HFrEF and 35 age‐matched and sex‐matched healthy controls were prospectively recruited. After all standard echocardiographic measurements were obtained in the left decubitus position, all subjects underwent postural stress testing, which consisted of changing from semi‐sitting position to passive leg‐lifting. During a median follow‐up period of 12.2 months, 21 (21%) patients developed adverse cardiovascular events. In patients without adverse cardiovascular events, the stroke volume index (SVi) significantly changed from 28 ± 8 to 35 ± 10 mL/m² (P < 0.001) during combined postural stress. By contrast, ΔSVi during combined dynamic postural stress was significantly smaller in patients with cardiovascular events than in those without events (ΔSVi 3.4 ± 4.0 vs. 6.4 ± 3.8 mL/m², P = 0.002), which indicated severely diseased heart operated on a relatively flat portion of the Frank–Starling curve. In a multivariate Cox proportional hazard analysis, ΔSVi (hazard ratio 0.81, P = 0.02) was an independent predictor of future adverse cardiovascular events.

Conclusions

The combined assessment of dynamic postural stress is a non‐invasive, simple, quick, and easy‐to‐use clinical tool for assessing preload reserve and risk stratification in HFrEF patients.

Microstructure of the juvenile sheep aortic valve hinge region and the trilamellar sliding hypothesis

Background: The aortic valve mechanism performs extremely sophisticated functions which depend on the microstructure of its component parts. The hinge mechanism of the aortic leaflets plays a crucial part in the overall function. However, the detailed microstructure and its relation to function has not been adequately studied.

Methods: The aortic roots of juvenile sheep were fixed under physiologic pressure. Sections through all three sinuses were then performed to illustrate the microstructure of the hinge mechanism in different regions of the aortic root.

Results: The hinge region in the different sinuses showed unique microstructure with a trilamellar topology with a dominant core consisting of glycosaminoglycans. The exact arrangement of the trilamellar structures varies around the aortic sinuses, which could have functional implications. These features allow the hinge to perform its complex functions through what we have described as “the trilamellar sliding hypothesis”.

Conclusion: The microstructure of the hinge mechanism is unique and enables it to perform it sophisticated functions.

Left ventricular-arterial coupling is associated with prolonged mechanical ventilation in severe post-cardiac surgery patients: an observational study

Background

Weaning post-cardiac surgery patients from mechanical ventilation (MV) poses a big challenge to these patients. Optimized left ventricular-arterial coupling (VAC) may be crucial for reducing the MV duration of these patients. However, there is no research exploring the relationship between VAC and the duration of MV. We performed this study to investigate the relationship between left ventricular-arterial coupling (VAC) and prolonged mechanical ventilation (MV) in severe post-cardiac surgery patients.

Methods

This was a single-center retrospective study of 56 severe post-cardiac surgery patients from January 2015 to December 2017 at the Department of Critical Care Medicine of Peking Union Medical College Hospital. Patients were divided into two groups according to the duration of MV (PMV group: prolonged mechanical ventilation group, MV > 6 days; Non-PMV group: non-prolonged mechanical ventilation group, MV ≤ 6 days). Hemodynamics and tissue perfusion data were collected or calculated at admission (T0) and 48 h after admission (T1) to the ICU.

Results

In terms of hemodynamic and tissue perfusion data, there were no differences between the two groups at admission (T0). Compared with the non-prolonged MV group after 48 h in the ICU (T1), the prolonged MV group had significantly higher values for heart rate (108 ± 13 vs 97 ± 12, P = 0.018), lactate (2.42 ± 1.24 vs.1.46 ± 0.58, P < 0.001), and Ea/Ees (5.93 ± 1.81 vs. 4.05 ± 1.20, P < 0.001). Increased Ea/Ees (odds ratio, 7.305; 95% CI, 1.181–45.168; P = 0.032) and lactate at T1 (odds ratio, 17.796; 95% CI, 1.377–229.988; P = 0.027) were independently associated with prolonged MV. There was a significant relationship between Ea/Ees_T1 and the duration of MV (r = 0.512, P < 0.01). The area under the receiver operating characteristic (AUC) of the left VAC for predicting prolonged MV was 0.801, and the cutoff value for Ea/Ees was 5.12, with 65.0% sensitivity and 90.0% specificity.

Conclusions

Left ventricular-arterial coupling was associated with prolonged mechanical ventilation in severe post-cardiac surgery patients. The assessment and optimization of left VAC might be helpful in reducing duration of MV in these patients.

Ventriculo-Arterial Coupling Analysis Predicts the Hemodynamic Response to Norepinephrine in Hypotensive Postoperative Patients: A Prospective Observational Study

OBJECTIVES

The objectives of the present study were to evaluate, in patients with persistent arterial hypotension in the immediate postcardiac surgery period, the effects of norepinephrine infusion on ventriculo-arterial coupling, its determinants: arterial elastance and end-systolic ventricular elastance, and to test the ability of arterial elastance to end-systolic ventricular elastance ratio to predict stroke volume increases.

DESIGN

Prospective observational study.

SETTING

Cardiac-vascular surgical ICU.

PATIENTS

Twenty-eight postoperative cardiac surgery patients, in whom physicians decided to administer norepinephrine infusion, were included.

MEASUREMENTS AND MAIN RESULTS

Arterial pressure, stroke volume index, cardiac index, indexed total peripheral resistance, arterial compliance, arterial elastance, and end-systolic ventricular elastance, were measured before and after norepinephrine infusion. We estimated ventriculo-arterial coupling by the arterial elastance to end-systolic ventricular elastance ratio and defined stroke volume responders by a stroke volume increase greater than or equal to 15%. Twenty-two of the 28 subjects had altered ventriculo-arterial coupling (1.87 [1.57-2.51] vs 1.1 [1-1.18]). Fifteen of the 28 subjects (54%) were stroke volume responders. At baseline, stroke volume responders had similar arterial pressure, higher indexed total peripheral resistance, arterial elastance, arterial elastance to end-systolic ventricular elastance ratio (2.21 [1.69-2.89] vs 1.33 [1.1-1.56]; p < 0.05), and lower arterial compliance, indexed total peripheral resistance and cardiac index. Norepinephrine significantly increased arterial pressure in all subjects. In stroke volume responders, norepinephrine increased arterial elastance, end-systolic ventricular elastance, cardiac index, and improved arterial elastance/end-systolic ventricular elastance coupling. The baseline arterial elastance to end-systolic ventricular elastance ratio predicted stroke volume responsiveness (area under the curve [95% CI], 0.87 [0.71-1]; p < 0.0001).

CONCLUSIONS

In patients with arterial hypotension norepinephrine increased end-systolic ventricular elastance and arterial elastance. The effects of norepinephrine on stroke volume depend on baseline ventriculo-arterial coupling. Although norepinephrine infusion corrects arterial hypotension in all subjects, increase of stroke volume occurred only in subjects with altered ventriculo-arterial coupling.