Left Ventricular End-Diastolic Pressure Predicts Survival in Coronary Artery Bypass Graft Surgery Patients

Left Atrial Strain as a Single Parameter to Predict Left Ventricular Diastolic Dysfunction and Elevated Left Ventricular Filling Pressure in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

OBJECTIVE

Left ventricular diastolic dysfunction (LVDD) is very common among patients undergoing cardiac surgery and is associated with increased mortality and morbidity. The present study tested the hypothesis of whether left atrial strain (LAS) can be used as a single parameter to predict LVDD (per 2016 LVDD evaluation guidelines) and elevated left ventricular filling pressure (LVFP) (ie, LVDD grades II and III) in patients scheduled for off-pump coronary artery bypass grafting (OPCABG) surgery.

DESIGN

A prospective observational study.

SETTINGS

Tertiary-care level hospital.

PARTICIPANTS

The study comprised 60 patients undergoing elective OPCABG.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Transthoracic echocardiography was performed within 24 hours of surgery by an anesthesiologist. LVDD was graded per American Society of Echocardiography/European Association of Cardiovascular Imaging recommendations for 2016 LVDD guidelines. Left atrial (LA) function was evaluated using two-dimensional strain measurements obtained with the speckle-tracking echocardiography technique. Receiver operating characteristic curves were constructed, and the area under the curve was derived for the prediction of elevated LVFP by LAS. Fourteen (23.3%) patients had elevated LVFP. Global LA reservoir strain (LAS_r) reduced significantly as the LVDD grade worsened (28.9% ± 8.3%, 21.8% ± 7.2%, 15.6% ± 4.5% and 11.9% ± 1.3%, respectively, for normal LV diastolic function and grades I, II, and III LVDD; p < 0.0001). Similar trends were noted for other components of LAS; namely, global LA conduction, global LA contraction strain, and LAS rate. The ability to predict high LVFP with LAS_r was statistically significant, with an area under the receiver operating characteristic curve of 0.92 (confidence interval 0.82-0.97; p < 0.001), and a Youden's index for LAS_r of 19% was obtained with 85.71% sensitivity and 84.78% specificity. The ability of LAS and its components to predict increased LVFP in various subpopulations (normal v reduced ejection fraction) yielded statistically significant results.

CONCLUSIONS

In patients scheduled for OPCABG, cardiac anesthesiologists successfully could measure LAS with speckle-tracking echocardiography in the preoperative period. LAS as a single parameter was significantly associated with the grade of LVDD. LAS_r decreased significantly with worsening grade of LVDD. Furthermore, an LAS_r value <19% significantly predicted a high LVFP, and LAS_r predicted high LVFP in both preserved and reduced ejection fraction equally well.

Meta-analysis of echocardiographic quantification of left ventricular filling pressure

Aims

The clinical reliability of echocardiographic surrogate markers of left ventricular filling pressures (LVFPs) across different cardiovascular pathologies remains unanswered. The main objective was to evaluate the evidence of how effectively different echocardiographic indices estimate true LVFP.

Methods and results

Design: this is a systematic review and meta‐analysis. Data source: Scopus, PubMed and Embase. Eligibility criteria for selecting studies were those that used echocardiography to predict or estimate pulmonary capillary wedge pressure or left ventricular end‐diastolic pressures. Twenty‐seven studies met criteria. Only eight studies (30%) reported both correlation coefficient and bias between non‐invasive and invasively measured LVFPs. The majority of studies (74%) recorded invasive pulmonary capillary wedge pressure as a surrogate for left ventricular end‐diastolic pressures. The pooled correlation coefficient overall was r = 0.69 [95% confidence interval (CI) 0.63–0.75, P < 0.01]. Evaluation by cohort demonstrated varying association: heart failure with preserved ejection fraction (11 studies, n = 575, r = 0.59, 95% CI 0.53–0.64) and heart failure with reduced ejection fraction (8 studies, n = 381, r = 0.67, 95% CI 0.61–0.72).

Conclusions

Echocardiographic indices show moderate pooled association to invasively measured LVFP; however, this varies widely with disease state. In heart failure with preserved ejection fraction, no single echocardiography‐based metric offers a reliable estimate. In heart failure with reduced ejection fraction, mitral inflow‐derived indices (E/e′, E/A, E/Vp, and EDcT) have reasonable clinical applicability. While an integrated approach of several echocardiographic metrics provides the most promise for estimating LVFP reliably, such strategies need further validation in larger, patient‐specific studies.

Targeting elevated left ventricular end-diastolic pressure following primary percutaneous coronary intervention for ST-segment elevation myocardial infarction – a phase one safety and feasibility study

Introduction:

Elevated left ventricular end diastolic pressure (LVEDP) is an independent predictor of mortality and heart failure in patients with ST-segment elevation myocardial infarction (STEMI). Whether lowering elevated LVEDP improves outcomes remains unknown.

Methods:

This non-randomized, single blinded study with prospective enrolment and sequential group allocation recruited patients undergoing primary percutaneous coronary intervention for STEMI with LVEDP ⩾ 20 mmHg measured immediately after primary percutaneous coronary intervention. The intervention arm (n=10) received furosemide 40 mg intravenous bolus plus escalating doses of glyceryl trinitrate (100 µg per min to a maximum of 1000 µg) during simultaneous measurement of LVEDP. The control group (n=10) received corresponding normal saline boluses with simultaneous measurement of LVEDP (10 readings over 10 min). Efficacy endpoints were final LVEDP achieved, and the dose of glyceryl trinitrate needed to reduce LVEDP by ⩾ 20%. Safety endpoint was symptomatic hypotension (systolic blood pressure &lt; 90 mmHg).

Results:

From 1 April 2017 to 23 August 2017 we enrolled 20 patients (age: 64±9 years, males: 60%, n=12, anterior STEMI: 65%, n=13). The mean LVEDP for the whole cohort (n=20) was 29±4 mmHg (intervention group: 28±3 mmHg vs. control group: 31±5 mmHg; p=0.1). The LVEDP dropped from 28±3 to 16±2 mmHg in the glyceryl trinitrate + furosemide group (p &lt;0.01) but remained unchanged in the control group. The median dose of glyceryl trinitrate required to produce ⩾ 20% reduction in LVEDP in the intervention group was 200 µg (range: 100–800). One patient experienced asymptomatic decline in systolic blood pressure to below 90 mmHg. There was no correlation between LVEDP and left ventricular ejection fraction.

Conclusion:

The administration of glyceryl trinitrate plus furosemide in patients with elevated LVEDP following primary percutaneous coronary intervention for STEMI safely reduces LVEDP.

Elevated left ventricular end diastolic pressure is associated with increased risk of contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention

AIMS

To study the correlation between intra-procedural left ventricular end-diastolic pressure (LVEDP) and the development of contrast-induced acute kidney injury (CI-AKI) in patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A single center retrospective observational study compared clinical and hemodynamic characteristics of patients who developed post-PCI CI-AKI with those did not. CI-AKI was defined as an absolute increase in serum creatinine ≥0.5 mg/dl or an increase ≥25% from baseline 48-72 h after the administration of contrast medium. Among 1301 consecutive patients who underwent PCI, 125 patients (9.6%) developed CI-AKI. The CI-AKI group had a higher average LVEDP (18.4 ± 8.7 vs 14.4 ± 6.6 mm Hg; p < .0001) and higher prevalence of elevated LVEDP (≥20 mm Hg) than those without CI-AKI (47.2% vs 23.3%, p < .0001). After adjustments, elevated LVEDP remained independently associated with CI-AKI (OR 2.21; 95% CI 1.40-3.50). LVEDP predicted the development of CI-AKI with a receiver operating characteristic area under curve (AUC) of 0.64. The association between elevated LVEDP and the risk of CI-AKI was stronger in patients with reduced ejection fraction (EF ≤ 40%) (OR = 4.08; 95% CI: 1.68-9.91) than those with preserved EF (OR = 1.69; 95% CI: 0.94-3.04) (p value for interaction = .0003). Patients who had LVEDP ≥ 20 mm Hg and LVEF ≤ 40% had a post-PCI incidence rate of developing CI-AKI of 36.5%.

CONCLUSIONS

Elevated intra-procedural LVEDP (≥20 mm Hg) is independently associated with increased risk of CI-AKI for patients undergoing cardiac catheterization and PCI, especially in the setting of reduced LVEF (≤40%).

Therapeutic Effects of Nrf2 Activation by Bardoxolone Methyl in Chronic Heart Failure

Oxidative stress plays an important role in the pathogenesis of chronic heart failure (CHF) in many tissues. Increasing evidence suggests that systemic activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling can protect against postinfarct cardiac remodeling by reducing oxidative stress. However, it remains to be elucidated if Nrf2 activation exerts therapeutic effects in the CHF state. Here, we investigated the beneficial hemodynamic effects of bardoxolone methyl (2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid methyl ester, CDDO-Me), a pharmacological activator of Nrf2, in a rodent model of CHF. Based on echocardiographic analysis, rats at 12 weeks post-myocardial infarction (MI) were randomly split into four groups. CDDO-Me (5 mg/kg, i.p.) was administered daily for another 2 weeks in sham and CHF rats and compared with vehicle treatment. Echocardiographic and hemodynamic analysis suggest that short-term CDDO-Me administration increased stroke volume and cardiac output in CHF rats and decreased left ventricle end-diastolic pressure. Molecular studies revealed that CDDO-Me-induced cardiac functional improvement was attributed to an increase of both Nrf2 transcription and translation, and a decrease of oxidative stress in the noninfarcted areas of the heart. Furthermore, CDDO-Me reduced NF-κB binding and increased Nrf2 binding to the CREB-binding protein, which may contribute to the selective increase of Nrf2 downstream targets, including NADPH Oxidase Quinone 1, Heme Oxygenase 1, Catalase, and Glutamate-Cysteine Ligase Catalytic Subunit, and the attenuation of myocardial inflammation in CHF rats. Our findings suggest that Nrf2 activation may provide beneficial cardiac effects in MI-mediated CHF. SIGNIFICANCE STATEMENT: Chronic heart failure (CHF) is the leading cause of death among the aged worldwide. The imbalance between pro- and antioxidant pathways is a determinant in the pathogenesis of CHF. Systemic activation of Nrf2 and antioxidant protein signaling by bardoxolone methyl may have beneficial effects on cardiac function and result in improvements by enhancing antioxidant enzyme expression and attenuating myocardial inflammation.

Cardio-autonomic functions and sleep indices before and after coronary artery bypass surgery

BACKGROUND:

Earlier studies showed a short-term impairment of cardio-autonomic functions following coronary artery bypass grafting (CABG). There is a lack of consistency in the time of recovery from this impairment. Studies have attributed the post-CABG atrial fibrillation to preexisting obstructive sleep apnea (OSA) without an objective sleep assessment. The aim of this study was to evaluate the effect of CABG on cardio-autonomic and hemodynamic functions and on OSA indices in patients with ischemic heart disease (IHD).

METHODS:

Cardio-autonomic function using heart rate variability indices, hemodynamic parameters, and sleep studies were performed in 26 patients with stable IHD before, on day-6, and day-30 post-CABG surgery.

RESULTS:

The high-frequency powers of normalized R-R intervals significantly (P = 0.002) increased from the preoperative value of 46.09 to 66.52 on day-6 and remained unchanged on day-30 postsurgery. In contrary, the low-frequency powers of normalized R-R interval decreased from 53.91 to 33.48 during the same period (P = 0.002) and remained unchanged on day 30 postsurgery. Baroreceptor sensitivity, obstructive and central apnea indices, desaturation index, and lowest O₂ saturation were not significantly different between preoperative, day-6, and day-30 postsurgery.

CONCLUSION:

Our study revealed that recovery of autonomic functions following CABG occurs as early as 30 days of postsurgery. CABG does not seem to have short-term effects on sleep study indices. However, long-term effects need further evaluation.

Burden and Prevention of Adverse Cardiac Events in Patients with Concomitant Chronic Heart Failure and Coronary Artery Disease: A Literature Review

Background

Chronic heart failure (HF) or coronary artery disease (CAD) confers risk for thromboembolism and secondary adverse cardiac events (ACEs) (e.g., mortality, myocardial infarction, and stroke). When HF and CAD occur concomitantly, ACE risk is reported to be elevated. We investigated ACEs, their epidemiology, and the resulting burden among patients with concomitant HF and CAD through a structured review of recent literature. Antithrombotic treatment for ACE prevention was assessed.

Methods

Pertinent databases (PubMed, other) were searched for relevant articles published from January 2004 to March 2015. Data collected included ACE incidence, healthcare resource use, costs, change in quality of life attributed to ACEs, and treatment practice for prevention of ACEs in patients with concomitant HF and CAD.

Results

Mortality rates for patients with both HF and CAD ranged from 4.9–12.3% at 30 days to 13.7–86% for periods between 9.9 months and 10 years. Incidence of ACEs among HF patients with CAD is, respectively, at least 82% and 15% higher than for patients without HF or without CAD, except for stroke investigated in two studies. All‐cause and HF‐related hospitalization is the main driver of the economic burden in patients with HF, the majority of whom had CAD origin. Despite high prevalence of ischemic complications, there is limited evidence to support the use of warfarin‐type antithrombotics among HF patients.

Conclusion

This study confirms that patients with concomitant HF and CAD are at elevated risk for ACEs and suggests the need for effective new antithrombotic treatments to further decrease ischemic complication rates in this population.

Using cardiac magnetic resonance imaging to evaluate cardiac function and predict outcomes in patients with valvular heart disease

OBJECTIVE

In valvular heart disease, elevated left atrial and pulmonary pressures contribute to right ventricular strain and, ultimately, right ventricle failure. Elevated pulmonary artery (PAP) and left ventricular end diastolic pressures are used as markers of right ventricle dysfunction and correlate with poor outcomes. Using cardiac magnetic resonance imaging (CMR), it is possible to directly quantify both left and right ventricular ejection function (LVEF and RVEF), and here, we compare CMR with traditional markers as outcome predictors.

METHODS

A retrospective review of prospectively collected data was performed for patients from January 2004 to February 2008 at a single center (n = 103). Patients were divided into those receiving CMR (n = 56) and those receiving only catheterization (n = 47). Univariate and multivariate logistic regression models were applied to determine predictors of mortality. Finally, predictive models for mortality using PAP, mean PAP, and left ventricular end diastolic pressure were compared to models using LVEF and RVEF obtained from CMR.

RESULTS

Preoperative average CMR LVEF and RVEF were 57% and 46%, respectively. Only age emerged as an isolated predictor of mortality (P = 0.01) within the univariate models. Stepwise regression models were created using the catheterization or CMR data. When compared, the CMR model has a slightly better R, c (prediction accuracy), and sensitivity/specificity (0.22 vs 0.28, 0.77 vs 0.82, and 0.63/0.62 vs 0.69/0.64, respectively).

CONCLUSIONS

Within our population, LVEF and RVEF predict mortality as least as well as traditional catheterization values. Additionally, CMR may identify of elevated PAPs caused by right ventricle dysfunction and those due to other causes, allowing these other causes to be addressed preoperatively.