Optimizing cardiovascular imaging in Staphylococcus aureus endocarditis.

INTRODUCTION: The shift toward value-based health care drives physicians to examine opportunities to optimize use of healthcare resources. There is discordance between providers' use of cardiovascular imaging (CVI) in assessing patients for infective endocarditis (IE) with Staphylococcus aureus bacteremia (SAB). An evidence-based algorithm was created to minimize variation of CVI use. The primary objective was to ensure sensitivity of the algorithm to recommend CVI in patients suspected of IE. METHODS: A retrospective review evaluated patients at Ochsner Medical Center who developed SAB between 1/1/13 and 12/31/14. Predefined patient demographics, use of CVI, outcomes, and 12-week follow-up for readmission after first positive blood culture were collected from chart review. The created algorithm was applied retrospectively to determine its sensitivity and specificity in recommending the right CVI test. RESULTS: 181 patients admitted were admitted with SAB, of which 114 (63%) were male. There were 115 TTEs and 55 TEEs performed. Out of 15 patients diagnosed with IE, 3 were found on TTE and 12 were found on TEE. The algorithm would have recommended a TEE in all 15 patients who had high-risk features for IE and a true diagnosis of IE, suggesting a sensitivity of 100% and specificity of 74.7% for the algorithm to have recommended a highly sensitive CVI modality. CONCLUSION: This algorithm optimizes CVI for diagnosing IE in patients with SAB. As healthcare adapts to a value-based system, use of best-practice algorithms will promote consistency in practice among providers and help optimize patient outcomes and use of resources.

Cardiovascular effects of preeclampsia.

PURPOSE OF REVIEW: Preeclampsia complicates 3-5% of first and 15% of subsequent pregnancies. This study reviews the evidence of increase cardiovascular risk in these women. RECENT FINDINGS: Women with preeclampsia are at two-fold higher risk for development of coronary artery disease, stroke and death, and four-fold increased risk of heart failure. Preeclampsia developed in early part of pregnancy confers greater risk than later in pregnancy. Common factors that predispose women to preeclampsia also confer high risk for developing cardiovascular disease include obesity, metabolic abnormalities, dyslipidaemia, insulin resistance, heightened inflammatory responses, hypercoagulable states and endothelia dysfunction. SUMMARY: Patients with preeclampsia should be screened at regular intervals by a preventive cardiologist and treated accordingly.

Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis.

PURPOSE: Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity. METHODS: This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVACEQ ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTILVOT / VTIMV. All-cause mortality data were collected retrospectively. RESULTS: A total of 64 patients with DMS and 24 patients with RMS were identified. MVACEQ was larger in patients with DMS (1.43 ± 0.4 cm2 ) than RMS (0.9 ± 0.3 cm2 ) by ~0.5 cm2 (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVACEQ ≤1.5 and MVACEQ ≤1.0 cm2 (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVACEQ ≤1.0 cm2 and DMSI ≤0.35, suggesting severe stenosis severity. CONCLUSION: Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Discordant left and right ventricular optimal atrioventricular and interventricular delays during biventricular pacemaker optimization.

Echocardiography-guided optimization of atrioventricular (AV) delay (AVD) improves left ventricular (LV) filling, and optimized interventricular delay (VVD) leads to further improvement in cardiac output in patients with biventricular (Biv) pacing. Investigators use LV filling and ejection to optimize AV and VV delay in patients with Biv pacing. Effect of such optimization on right-sided hemodynamics remains unknown. In our experience, few patients experience worsening of right ventricle (RV) hemodynamics when LV parameters are optimized. We present a series of cases where we observed suboptimal RV filling or ejection at optimal AVD and VVD for LV. This RV-LV discordance may contribute to nonresponder rate to cardiac resynchronization therapy (CRT) and should be evaluated in a consecutive series of CRT nonresponder patients to help improve CRT response.

Shortening of atrioventricular delay at increased atrial paced heart rates improves diastolic filling and functional class in patients with biventricular pacing.

BACKGROUND: Use of rate adaptive atrioventricular (AV) delay remains controversial in patients with biventricular (Biv) pacing. We hypothesized that a shortened AV delay would provide optimal diastolic filling by allowing separation of early and late diastolic filling at increased heart rate (HR) in these patients. METHODS: 34 patients (75 ± 11 yrs, 24 M, LVEF 34 ± 12%) with Biv and atrial pacing had optimal AV delay determined at baseline HR by Doppler echocardiography. Atrial pacing rate was then increased in 10 bpm increments to a maximum of 90 bpm. At each atrial pacing HR, optimal AV delay was determined by changing AV delay until best E and A wave separation was seen on mitral inflow pulsed wave (PW) Doppler (defined as increased atrial duration from baseline or prior pacemaker setting with minimal atrial truncation). Left ventricular (LV) systolic ejection time and velocity time integral (VTI) at fixed and optimal AV delay was also tested in 13 patients. Rate adaptive AV delay was then programmed according to the optimal AV delay at the highest HR tested and patients were followed for 1 month to assess change in NYHA class and Quality of Life Score as assessed by Minnesota Living with Heart Failure Questionnaire. RESULTS: 81 AV delays were evaluated at different atrial pacing rates. Optimal AV delay decreased as atrial paced HR increased (201 ms at 60 bpm, 187 ms at 70 bpm, 146 ms at 80 bpm and 123 ms at 90 bpm (ANOVA F-statistic = 15, p = 0.0010). Diastolic filling time (P < 0.001 vs. fixed AV delay), mitral inflow VTI (p < 0.05 vs fixed AV delay) and systolic ejection time (p < 0.02 vs. fixed AV delay) improved by 14%, 5% and 4% respectively at optimal versus fixed AV delay at the same HR. NYHA improved from 2.6 ± 0.7 at baseline to 1.7 ± 0.8 (p < 0.01) 1 month post optimization. Physical component of Quality of Life Score improved from 32 ± 17 at baseline to 25 ± 12 (p < 0.05) at follow up. CONCLUSIONS: Increased heart rate by atrial pacing in patients with Biv pacing causes compromise in diastolic filling time which can be improved by AV delay shortening. Aggressive AV delay shortening was required at heart rates in physiologic range to achieve optimal diastolic filling and was associated with an increase in LV ejection time during optimization. Functional class improved at 1 month post optimization using aggressive AV delay shortening algorithm derived from echo-guidance at the time of Biv pacemaker optimization.

Prosthesis-patient mismatch following aortic and mitral valves replacement - A comprehensive review.

Prothesis-patient mismatch (PPM) occurs when there is a mismatch between the effective orifice area (EOA) of the prosthetic valve and the required cardiac output to meet the need of the patient's body surface area (BSA). The clinical threshold for PPM occurs when the indexed effective orifice area (iEOA) is ≤0.65 cm2/m2 for the aortic valve prosthesis, and ≤ 1.20 cm2/m2 for the mitral valve prosthesis. The wide variation of reported incidence of PPM is most likely attributed to the variation in the methods of calculating iEOA [(for e.g., using continuity equation across the prosthesis versus using projected EOA (generated by the industry)]. Newer generation mechanical valves have shown less PPM than older generation, and stentless bioprosthesis have less PPM than stented prosthesis. Long-term clinical outcome of PPM is associated with adverse cardiovascular events especially in the presence of pre-existing left ventricle dysfunction or with concomitant procedure such as coronary artery bypass graft surgery. Strategies to mitigate the risk of PPM such as aortic root replacement in patients with the small aortic annulus should be utilized. Accurate assessment of the patient's annular size and indexing the effective orifice area (EOA) of the prosthesis to patient's BSA at the time of prosthesis implantation are important steps to preventing future PPM.

Watchman FLX Implantation for Challenging Left Atrial Appendage Anatomy: Case-Based Discussion.

Left atrial appendage (LAA) occlusion devices provided an acceptable and valid alternative to anticoagulation among patients with atrial fibrillation who carry high bleeding risk. Watchman device is non-inferior to oral anticoagulation to prevent cerebrovascular accidents. The presence of a longer distal portion of the older generation Watchman led to exclusion of patients with prohibitive anatomy of the LAA such as chicken-wing morphology or shallow LAA. Watchman FLX provides a wider range of sizes and can be implanted with complex anatomy or shallow LAA. In the case series, we discuss 3 patients with challenging LAA anatomy that underwent successful Watchman FLX implantation.

Automated analysis of limited echocardiograms: Feasibility and relationship to outcomes in COVID-19.

Background: As automated echocardiographic analysis is increasingly utilized, continued evaluation within hospital settings is important to further understand its potential value. The importance of cardiac involvement in patients hospitalized with COVID-19 provides an opportunity to evaluate the feasibility and clinical relevance of automated analysis applied to limited echocardiograms. Methods: In this multisite US cohort, the feasibility of automated AI analysis was evaluated on 558 limited echocardiograms in patients hospitalized with COVID-19. Reliability of automated assessment of left ventricular (LV) volumes, ejection fraction (EF), and LV longitudinal strain (LS) was assessed against clinically obtained measures and echocardiographic findings. Automated measures were evaluated against patient outcomes using ROC analysis, survival modeling, and logistic regression for the outcomes of 30-day mortality and in-hospital sequelae. Results: Feasibility of automated analysis for both LVEF and LS was 87.5% (488/558 patients). AI analysis was performed with biplane method in 300 (61.5%) and single plane apical 4- or 2-chamber analysis in 136 (27.9%) and 52 (10.7%) studies, respectively. Clinical LVEF was assessed using visual estimation in 192 (39.3%), biplane in 163 (33.4%), and single plane or linear methods in 104 (21.2%) of the 488 studies; 29 (5.9%) studies did not have clinically reported LVEF. LV LS was clinically reported in 80 (16.4%). Consistency between automated and clinical values demonstrated Pearson's R, root mean square error (RMSE) and intraclass correlation coefficient (ICC) of 0.61, 11.3% and 0.72, respectively, for LVEF; 0.73, 3.9% and 0.74, respectively for LS; 0.76, 24.4ml and 0.87, respectively, for end-diastolic volume; and 0.82, 12.8 ml, and 0.91, respectively, for end-systolic volume. Abnormal automated measures of LVEF and LS were associated with LV wall motion abnormalities, left atrial enlargement, and right ventricular dysfunction. Automated analysis was associated with outcomes, including survival. Conclusion: Automated analysis was highly feasible on limited echocardiograms using abbreviated protocols, consistent with equivalent clinically obtained metrics, and associated with echocardiographic abnormalities and patient outcomes.

Pre-ejection period by radial artery tonometry supplements echo Doppler findings during biventricular pacemaker optimization.

BACKGROUND: Biventricular (Biv) pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP) assessment by radial artery tonometry in guiding Biv pacemaker optimization. METHODS: Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV) ejection fraction (EF) 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI), ejection time (ET), myocardial performance index (MPI), radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. RESULTS: Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p < 0.001), LV VTI (15.9 ± 4.8 cm to 18.4 ± 5.1 cm, p < 0.001) and MPI (0.57 ± 0.2 to 0.45 ± 0.13, p < 0.001) and in PEP (246.7 ± 36.1 ms to 234.7 ± 35.5 ms, p = 0.003), PEP/ET (0.88 ± 0.21 to 0.79 ± 0.17, p < 0.001), and PEP/VTI (17.3 ± 7 to 13.78 ± 4.7, p < 0.001). The correlation between comprehensive echo Doppler and radial artery tonometry-PEP guided optimal atrioventricular delay (AVD) and optimal interventricular delay (VVD) was 0.75 (p < 0.001) and 0.69 (p < 0.001) respectively. In 29 patients with follow up assessment, New York Heart Association (NYHA) class reduced from 2.5 ± 0.8 to 2.0 ± 0.9 (p = 0.004) at 1.8 ± 1.4 months. CONCLUSION: An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.

Impact of Preinfection Left Ventricular Ejection Fraction on Outcomes in COVID-19 Infection.

Coronavirus disease 2019 (COVID-19) has high infectivity and causes extensive morbidity and mortality. Cardiovascular disease is a risk factor for adverse outcomes in COVID-19, but baseline left ventricular ejection fraction (LVEF) in particular has not been evaluated thoroughly in this context. We analyzed patients in our state's largest health system who were diagnosed with COVID-19 between March 20 and May 15, 2020. Inclusion required an available echocardiogram within 1 year prior to diagnosis. The primary outcome was all-cause mortality. LVEF was analyzed both as a continuous variable and using a cutoff of 40%. Among 396 patients (67 ± 16 years, 191 [48%] male, 235 [59%] Black, 59 [15%] LVEF ≤40%), 289 (73%) required hospital admission, and 116 (29%) died during 85 ± 63 days of follow-up. Echocardiograms, performed a median of 57 (IQR 11-122) days prior to COVID-19 diagnosis, showed a similar distribution of LVEF between survivors and decedents (P = 0.84). Receiver operator characteristic analysis revealed no predictive ability of LVEF for mortality, and there was no difference in survival among those with LVEF ≤40% versus >40% (P = 0.49). Multivariable analysis did not change these relationships. Similarly, there was no difference in LVEF based on whether the patient required hospital admission (56 ± 13 vs 55 ± 13, P = 0.38), and patients with a depressed LVEF did not require admission more frequently than their preserved-LVEF peers (P = 0.87). A premorbid history of dyspnea consistent with symptomatic heart failure was not associated with mortality (P = 0.74). Among patients diagnosed with COVID-19, pre-COVID-19 LVEF was not a risk factor for death or hospitalization.

Differentiating Constriction from Restriction (from the Mayo Clinic Echocardiographic Criteria).

Constrictive Pericarditis (CP) is a curable and reversible form of severe diastolic heart failure. We aimed to investigate the diagnostic accuracy of published echocardiographic Mayo Clinic Criteria in differentiating 107 patients with surgically proven CP from 30 patients with restrictive cardiomyopathy due to cardiac Amyloidosis. Five principal echocardiographic and Doppler variables were remeasured on preoperative transthoracic echocardiogram namely (1) respiration-related ventricular septal shift; (2) respiratory variation in mitral inflow E pulsed Doppler velocity; 3) tissue Doppler medial mitral annular e' velocity; (4) ratio of medial mitral annular e' to lateral mitral annular e' velocity; and 5) hepatic vein (HV) pulsed Doppler diastolic flow reversal ratio. Etiology of CP included viral/idiopathic or autoimmune (75%), postcardiac surgery (13%) and postradiation (7%). Univariate logistic regression analysis showed that (1) respiration related ventricular septal shift, (2) percentage change in Mitral E velocity, (3) medial e' velocity ≥9 cm/sec, (4) medial e'/lateral e' ratio ≥0.91, (5) HV diastolic reversal ratio ≥0.79 were associated with the diagnosis of CP. Multivariable logistic regression analyses showed that medial e' velocity ≥9 cm/s was independently associated with the diagnosis of CP. Respiration related ventricular septal shift had the highest sensitivity, whereas medial e' velocity ≥9 cm/s has the highest specificity to diagnose CP (Areas under curves 0.99, p 0.001). Combining respiration related ventricular septal shift with medial e' velocity ≥9 cm/s gave a desirable sensitivity (80%) and specificity (92%). Adding reversal ratio to this combination further increased the specificity (97%) but dropped the sensitivity (70%) to diagnose CP.

Prognostic Implications of Left Ventricular Hypertrophy.

Left ventricular hypertrophy (LVH) was one of the earliest studied echocardiographic characteristics of the left ventricle. As the myriad of measurable metrics has multiplied over recent years, this reliable and relevant variable can often be overlooked. In this paper, we discuss appropriate techniques for accurate analysis, underlying pathophysiology, and the contributions from various risk factors. The prognostic implications of LVH on stroke, serious arrhythmias, and sudden cardiac death are reviewed. Finally, we examine the effect of therapy to reduce LVH and the resultant clinical outcomes.

Quantitative assessment of pericardial delayed hyperenhancement helps identify patients with ongoing recurrences of pericarditis.

Objectives: Recurrences of pericarditis (RP) are often difficult to diagnose due to lack of clinical signs and symptoms during subsequent episodes. We aimed to investigate the value of quantitative assessment of pericardial delayed hyperenhancement (DHE) in diagnosing ongoing recurrences of pericarditis. Methods: Quantitative DHE was measured in 200 patients with established diagnosis of RP using cardiac MRI. Conventional clinical criteria for diagnosis of pericarditis were ≥2 of the following: chest pain, pericardial rub, ECG changes and new or worsening pericardial effusion. Results: A total of 67 (34%) patients were identified as having ongoing episode of recurrence at the time of DHE measurements. In multivariable analysis, chest pain (OR: 10.9, p<0.001) and higher DHE (OR: 1.32, p<0.001) were associated with ongoing recurrence of RP. Addition of DHE to conventional clinical criteria significantly increased the ability to diagnose ongoing recurrence (net reclassification improvement (NRI): 0.80, p<0.001; integrated discrimination improvement (IDI): 0.12, p<0.001). Among 150 patients with history of RP who presented with chest pain, higher DHE was still independently associated with ongoing recurrence (OR: 1.28, p<0.001), showed incremental value over clinical criteria (NRI: 0.76, p<0.001; IDI: 0.13, p<0.001) and demonstrated a sensitivity of 70% and specificity of 74%. Conclusion: Among patients with RP, quantitative DHE provided incremental information to diagnose ongoing recurrences over conventional clinical criteria of pericarditis. Quantitative DHE demonstrated acceptable test characteristics to diagnose ongoing recurrence even in RP patients presenting with chest pain.

Echocardiographic Assessment of Degenerative Mitral Stenosis: A Diagnostic Challenge of an Emerging Cardiac Disease.

Degenerative mitral stenosis (DMS) is characterized by decreased mitral valve (MV) orifice area and increased transmitral pressure gradient due to chronic noninflammatory degeneration and subsequent calcification of the fibrous mitral annulus and the MV leaflets. The "true" prevalence of DMS in the general population is unknown. DMS predominantly affects elderly individuals, many of whom have multiple other comorbidities. Transcatheter MV replacement techniques, although their long-term outcomes are yet to be tested, have been gaining popularity and may emerge as more effective and relatively safer treatment option for patients with DMS. Echocardiography is the primary imaging modality for evaluation of DMS and related hemodynamic abnormalities such as increased transmitral pressure gradient and pulmonary arterial pressure. Classic echocardiographic techniques used for evaluation of mitral stenosis (pressure half time, proximal isovelocity surface area, continuity equation, and MV area planimetry) lack validation for DMS. Direct planimetry with 3-dimensional echocardiography and color flow Doppler is a reasonable technique for determining MV area in DMS. Cardiac computed tomography is an essential tool for planning potential interventions or surgeries for DMS. This article reviews the current concepts on mitral annular calcification and its role in DMS. We then discuss the epidemiology, natural history, differential diagnosis, mechanisms, and echocardiographic assessment of DMS.

False-Positive Stress Echocardiograms: A Continuing Challenge.

BACKGROUND: Stress echocardiography is an integral test in the cardiac diagnostic laboratory and has high sensitivity and specificity. Despite the excellent specificity of stress echocardiography, we continue to see a subset of patients with false-positive tests (defined as <50% diameter stenosis on subsequent coronary angiography). These false-positive findings present a management challenge because it remains unclear if and how to treat these patients. METHODS: This article reviews relevant clinical studies and their outcomes. RESULTS: Studies suggest that a group of patients develops a hypertensive response to exercise and therefore may have false-positive stress echocardiography. Hence, superior blood pressure control prior to stress echocardiography may prevent some false-positive tests. In addition, a subset of patients has microvascular abnormalities, vasomotor changes, endothelial dysfunction, and/or small vessel coronary disease that can lead to false-positive stress echocardiography. CONCLUSION: The evidence is insufficient to state that a false-positive stress echocardiography in the absence of obstructive coronary artery disease portends a poor outcome, but considerable evidence shows that some of these patients have microvascular abnormalities and endothelial dysfunction and consequently may benefit from aggressive medical management and further testing.

ST Segment Elevation ECG Changes During Pharmacologic Stress With Regadenoson.

Regadenoson is a pharmacologic stress agent that has been widely adopted as an alternative over other pharmacologic vasodilator agents due to its ease of use, patient tolerance, and safety profile. We report the case of dynamic ST-segment elevation electrocardiogram changes after regadenoson injection during an inpatient single-photon emission computed tomography myocardial perfusion stress test, with subsequent coronary angiography revealing the presence of hemodynamically significant coronary artery disease. Our findings confirm that transient regadenoson-induced ST-segment elevations are a marker for hemodynamically significant disease even in the setting of low-risk SPECT perfusion images.

Left Atrial Size and Function in a Canine Model of Chronic Atrial Fibrillation and Heart Failure.

BACKGROUND: Our aim was to assess how atrial fibrillation (AF) induction, chronicity, and RR interval irregularity affect left atrial (LA) function and size in the setting of underlying heart failure (HF), and to determine whether AF effects can be mitigated by vagal nerve stimulation (VNS). METHODS: HF was induced by 4-weeks of rapid ventricular pacing in 24 dogs. Subsequently, AF was induced and maintained by atrial pacing at 600 bpm. Dogs were randomized into control (n = 9) and VNS (n = 15) groups. In the VNS group, atrioventricular node fat pad stimulation (310 µs, 20 Hz, 3-7 mA) was delivered continuously for 6 months. LA volume and LA strain data were calculated from bi-weekly echocardiograms. RESULTS: RR intervals decreased with HF in both groups (p = 0.001), and decreased further during AF in control group (p = 0.014), with a non-significant increase in the VNS group during AF. LA size increased with HF (p<0.0001), with no additional increase during AF. LA strain decreased with HF (p = 0.025) and further decreased after induction of AF (p = 0.0001). LA strain decreased less (p = 0.001) in the VNS than in the control group. Beat-by-beat analysis showed a curvilinear increase of LA strain with longer preceding RR interval, (r = 0.45, p <0.0001) with LA strain 1.1% higher (p = 0.02) in the VNS-treated animals, independent of preceding RR interval duration. The curvilinear relationship between ratio of preceding and pre-preceding RR intervals, and subsequent LA strain was weaker, (r = 0.28, p = 0.001). However, VNS-treated animals again had higher LA strain (by 2.2%, p = 0.002) independently of the ratio of preceding and pre-preceding RR intervals. CONCLUSIONS: In the underlying presence of pacing-induced HF, AF decreased LA strain, with little impact on LA size. LA strain depends on the preceding RR interval duration.