Infective endocarditis: trends, surgical outcomes, and controversies.

The number of hospitalizations and surgical cases of infective endocarditis (IE) are increasing. The aim of this study was to review these trends, surgical outcomes, and controversies related to IE. A search of MEDLINE of studies published between 1960 and 2018 was conducted. Search terms included "infective endocarditis", "history of", "trend", "epidemiology", "outcome", "medical management", "surgery", "indication", and "re-operative surgery", or any combination thereof. The United States has the highest incidence of IE in the world at 15 per 100,000 people, with increases in incidence due to the aging population as well as increasing rates of intravenous drug use (IVDU). National guidelines support early surgical intervention in specific clinical settings in both left and right-sided IE. However, only 11% of the evidence used in formulating guidelines for surgical therapy in IE are based on level A evidence. Ongoing controversies include whether to perform surgery in the setting of continued or recurrent IVDU in a patient with a prior valve operation, timing of surgery after acute stroke due to IE, and general indications for surgery for tricuspid valve IE. IE has a surging incidence and increasing burden on the healthcare system in the United States. Multiple controversies exist, and formulating level A evidence and multidisciplinary collaboration will be essential components to effectively treating this complex patient population.

Noninvasive estimation of pulmonary vascular resistance in pulmonary hypertension.

BACKGROUND: Determination of pulmonary vascular resistance (PVR) in patients with suspected or known pulmonary hypertension (PH) requires right heart catheterization. Our purpose was to use Doppler echocardiography to estimate PVR in patients with PH. METHODS: Patient population consisted of 52 patients (53 +/- 12 years; 35 females) who underwent Doppler echocardiography and right heart catheterization within 24 hours of each other. The ratio of peak tricuspid regurgitation velocity (TRV) and right ventricular outflow time-velocity integral (VTI(RVOT)) was measured via transthoracic echocardiography and correlated to invasively determined PVR. A linear regression equation was generated to determine PVR by echocardiography based upon the TRV/VTI(RVOT) ratio. PVR by echocardiography was compared to invasive PVR using Bland-Altman analysis. RESULTS: Significant correlation was demonstrated between TRV/VTI(RVOT) and PVR by catheterization (r = 0.73; P < 0.001). However, Bland-Altman analysis showed that agreement between PVR determined by echocardiography and invasive PVR was poor (bias = 0; standard deviation = 4.3 Wood units). In a subset of patients with invasive PVR < 8 Wood units (26 patients), correlation between TRV/VTI(RVOT) and invasive PVR was strong (r = 0.94; P < 0.001). In these patients, agreement between PVR by echocardiography and invasive PVR was satisfactory (bias = 0; standard deviation = 0.5 Wood units). There was no correlation between TRV/VTI(RVOT) and invasive PVR in patients with PVR > 8 Wood units (n = 26; r = 0.17). CONCLUSION: While TRV/VTI(RVOT) correlates significantly with PVR, using it to estimate PVR in a PH patient population cannot be recommended.

Relation of elevation in cardiac troponin I to clinical severity, cardiac dysfunction, and pulmonary congestion in patients with subarachnoid hemorrhage.

An increase in cardiac troponin I (cTnI) occurs often after aneurysmal subarachnoid hemorrhage (SAH), but its significance is not well understood. One hundred three patients with SAH were prospectively evaluated in the SAHMII Study to determine the relations of cTnI to clinical severity, systolic and diastolic cardiac function, pulmonary congestion, and length of intensive care unit stay. Echocardiographic ejection fraction, wall motion score, mitral inflow early diastolic (E) and mitral annular early (E') velocities were assessed. Thirty patients (29%) had mildly positive cTnI (0.1 to 1.0 ng/ml), 24 (23%) had highly positive cTnI (>1.0 ng/ml), and 49 (48%) had negative cTnI (<0.1 ng/ml). Highly positive cTnI was associated with worse neurologic disease, longer intensive care unit stay, and slight depression of ejection fraction (51 +/- 11% [p <0.05] vs 59 +/- 8% and 63 +/- 6% in mildly positive or negative cTnI groups, respectively). Highly positive cTnI was also associated with abnormal wall motion acutely (>1.31 ng/ml; 76% sensitivity, 91% specificity), which typically resolved within 5 to 10 days. Both mildly or highly positive cTnI were associated with acute diastolic dysfunction, with E/E' of 17 +/- 6 and 16 +/- 6 (both p <0.05) vs 13 +/- 4 in patients with negative cTnI. Prevalences of pulmonary congestion were 79% (p <0.05) in patients with highly positive cTnI, 53% (p <0.05) in patients with mildly positive cTnI, and 29% in cTnI-negative patients. In conclusion, highly positive cTnI with SAH was associated with clinical neurologic severity, systolic and diastolic cardiac dysfunction, pulmonary congestion, and longer intensive care unit stay. Even mild increases in cTnI were associated with diastolic dysfunction and pulmonary congestion.

The role of tissue Doppler and strain imaging in predicting response to CRT.

AIMS: Several echocardiographic methods have been proposed to assist in patient selection for cardiac resynchronization therapy (CRT). The prevailing hypothesis is that echocardiography may be superior to the electrocardiogram to qualify abnormalities in regional mechanical activation, because QRS widening is only a surrogate for ventricular dyssynchrony. METHODS AND RESULTS: This review will focus on tissue Doppler (TD) and strain imaging, including their advantages and disadvantages for patient selection for CRT. Colour-coded TD remains to be one of the most promising means to quantify dyssynchrony. Tissue Doppler velocity data have a more favourable signal-to-noise ratio compared with TD strain or strain rate imaging. However, velocity data are affected by Doppler angle of incidence and passive or tethering motion. A newer promising method is speckle-tracking echocardiography to calculate strain. An opposing wall delay in peak TD velocity > or =65 ms has been associated with clinical and ventricular response to CRT. The initial experience with speckle tracking used the short-axis view to calculate radial strain. An anterior-septal to posterior wall peak strain delay > or =130 ms has been associated with an ejection fraction response to CRT. CONCLUSION: Although no ideal echo-Doppler method has yet been discovered to select patients for CRT, technical refinements and advances in understanding of pathophysiology continue to favourably impact on potential clinical applications.

Left ventricular dyssynchrony acutely after myocardial infarction predicts left ventricular remodeling.

OBJECTIVES: We sought to identify predictors of left ventricular (LV) remodeling after acute myocardial infarction. BACKGROUND: Left ventricular remodeling after myocardial infarction is associated with an adverse long-term prognosis. Early identification of patients prone to LV remodeling is needed to optimize therapeutic management. METHODS: A total of 178 consecutive patients presenting with acute myocardial infarction who underwent primary percutaneous coronary intervention were included. Within 48 h of intervention, 2-dimensional echocardiography was performed to assess LV volumes, LV ejection fraction (LVEF), wall motion score index, left atrial dimension, E/E' ratio, and severity of mitral regurgitation. Left ventricular dyssynchrony was determined using speckle-tracking radial strain analysis. At 6-month follow-up, LV volumes, LVEF, and severity of mitral regurgitation were reassessed. RESULTS: Patients showing LV remodeling at 6-month follow-up (20%) had comparable baseline characteristics to patients without LV remodeling (80%), except for higher peak troponin T levels (p < 0.001), peak creatine phosphokinase levels (p < 0.001), wall motion score index (p < 0.05), E/E' ratio (p < 0.05), and a larger extent of LV dyssynchrony (p < 0.001). Multivariable analysis demonstrated that LV dyssynchrony was superior in predicting LV remodeling. Receiver-operating characteristic curve analysis demonstrated that a cutoff value of 130 ms for LV dyssynchrony yields a sensitivity of 82% and a specificity of 95% to predict LV remodeling at 6-month follow-up. CONCLUSIONS: Left ventricular dyssynchrony immediately after acute myocardial infarction predicts LV remodeling at 6-month follow-up.

Combined longitudinal and radial dyssynchrony predicts ventricular response after resynchronization therapy.

OBJECTIVES: The purpose of this study was to test the hypothesis that a combined echocardiographic assessment of longitudinal dyssynchrony by tissue Doppler imaging (TDI) and radial dyssynchrony by speckle-tracking strain may predict left ventricular (LV) functional response to cardiac resynchronization therapy (CRT). BACKGROUND: Mechanical LV dyssynchrony is associated with response to CRT; however, complex patterns may exist. METHODS: We studied 190 heart failure patients (ejection fraction [EF] 23 +/- 6%, QRS duration 168 +/- 27 ms) before and after CRT. Longitudinal dyssynchrony was assessed by color TDI for time to peak velocity (2 sites in all and 12 sites in a subgroup of 67). Radial dyssynchrony was assessed by speckle-tracking radial strain. The LV response was defined as > or =15% increase in EF. RESULTS: One hundred seventy-six patients (93%) had technically sufficient baseline and follow-up data available. Overall, 34% were EF nonresponders at 6 +/- 3 months after CRT. When both longitudinal dyssynchrony by 2-site TDI (> or =60 ms) and radial dyssynchrony (> or =130 ms) were positive, 95% of patients had an EF response; when both were negative, 21% had an EF response (p < 0.001 vs. both positive). The EF response rate was lowest (10%) when dyssynchrony was negative using 12-site TDI and radial strain (p < 0.001 vs. both positive). When either longitudinal or radial dyssynchrony was positive (but not both), 59% had an EF response. Combined longitudinal and radial dyssynchrony predicted EF response with 88% sensitivity and 80% specificity, which was significantly better than either technique alone (p < 0.0001). CONCLUSIONS: Combined patterns of longitudinal and radial dyssynchrony can be predictive of LV functional response after CRT.

Usefulness of tissue Doppler velocity and strain dyssynchrony for predicting left ventricular reverse remodeling response after cardiac resynchronization therapy.

The assessment of systolic dyssynchrony by echocardiography is useful in predicting a favorable response to cardiac resynchronization therapy (CRT). Tissue Doppler velocity and tissue Doppler longitudinal strain have been suggested for this purpose. This study compared parameters of systolic dyssynchrony derived from these 2 imaging modalities for their predictive values of CRT response. Two hundred fifty-six patients from 3 different centers who received CRT were followed for 6 +/- 3 months. Parameters of systolic dyssynchrony based on tissue Doppler velocity and strain imaging were assessed for the prediction of left ventricular (LV) reverse remodeling (reduction of LV end-systolic volume > or =15%). These included time to peak systolic velocity (or peak strain) of 12 LV segments to calculate the SD (Ts-SD or Tepsilon-SD), maximal difference in delay (Ts-Diff or Tepsilon-Diff), and opposite wall delay (Ts-OW or Tepsilon-OW). The septal-to-lateral delay (Ts-Sep-Lat or Tepsilon-Sep-Lat) was also measured. LV reverse remodeling, defined as improvement in end-systolic volume > or =15%, was observed in 141 patients (55%). All 4 tissue velocity parameters predicted LV reverse remodeling, and the areas under the receiver-operating characteristic curves were 0.86, 0.85, 0.84, and 0.79 for Ts-SD, Ts-Diff, Ts-OW, and Ts-Sep-Lat, respectively (all p <0.001). The cut-off values derived from receiver-operating characteristic curve analysis were 33 ms for Ts-SD, 100 ms for Ts-Diff, 90 ms for Ts-OW, and 60 ms for Ts-Sep-Lat, and their sensitivities were 93%, 92%, 81%, and 70%, with specificities of 78%, 68%, 80%, and 76%, respectively. In contrast, none of the longitudinal strain parameters predicted LV reverse remodeling. The areas under the receiver-operating characteristic curves ranged from 0.49 to 0.53 (all p = NS). The same conclusions were obtained in subgroup analyses of QRS duration (120 to 150 vs >150 ms) and ischemic or nonischemic cause of heart failure. In conclusion, parameters of tissue Doppler longitudinal velocity, but not longitudinal strain, predicted LV reverse remodeling after CRT.

Right ventricular function following cardiac resynchronization therapy.

The effect of cardiac resynchronization therapy (CRT) on right ventricular (RV) function has not been well described. The purpose of this study was to use tissue Doppler imaging to assess changes in RV function after CRT. Thirty-five patients with heart failure (age 65 +/- 10 years; 26 men) who underwent color tissue Doppler imaging of the right ventricle both immediately before CRT and >3 months (mean 6 +/- 3) after were studied. Myocardial systolic velocity was measured at the tricuspid annulus and basal and midventricular segments of the right ventricle free wall and averaged to obtain a measure of global RV function (RV S(m)). Left ventricular ejection fraction was also measured using biplane Simpson's method before and after CRT. RV S(m) significantly improved after CRT (5.4 +/- 1.9 to 7.1 +/- 2.6 cm/s; p <0.001), as did left ventricular ejection fraction (26 +/- 6% to 34 +/- 10%; p <0.001). Twenty-one of 35 patients (60%) showed an increase in RV S(m) > or =1 cm/s, with an increase > or =2 cm/s in 13 of those patients (37%). Improvement was seen in both ischemic and nonischemic patients and was independent of improvement in left ventricular ejection fraction and baseline left ventricular dyssynchrony. In conclusion, CRT resulted in improved RV function measured as RV S(m). CRT had beneficial effects on RV function independent of improvement in left ventricular ejection fraction.

Speckle-tracking radial strain reveals left ventricular dyssynchrony in patients with permanent right ventricular pacing.

OBJECTIVES: Speckle-tracking strain analysis was used to assess the effects of permanent right ventricular (RV) pacing on the heterogeneity in timing of regional wall strain and left ventricular (LV) dyssynchrony. BACKGROUND: Recent studies have shown detrimental effects of RV pacing, possibly related to the induction of LV dyssynchrony. METHODS: Fifty-eight patients treated with His bundle ablation and pacemaker implantation were studied. To assess the effect of RV pacing on time-to-peak radial strain of different LV segments, we applied speckle-tracking analysis to standard LV short-axis images. In addition, New York Heart Association (NYHA) functional class, LV volumes, and systolic function were assessed at baseline and after long-term RV pacing. RESULTS: At baseline, similar time-to-peak strain for the 6 segments was observed (mean 371 +/- 114 ms). In contrast, after a mean of 3.8 +/- 2.0 years of RV pacing, there was a marked heterogeneity in time-to-peak strain of the 6 segments. In 33 patients (57%), LV dyssynchrony, represented by a time difference > or =130 ms between the time-to-peak strain of the (antero)septal and the posterolateral segments, was present. In these patients, a deterioration of LV systolic function and NYHA functional class was observed. In 11 patients, an "upgrade" of the conventional pacemaker to a biventricular pacemaker resulted in partial reversal of the detrimental effects of RV pacing. CONCLUSIONS: Speckle-tracking analysis revealed that permanent RV pacing induced heterogeneity in time-to-peak strain, resulting in LV dyssynchrony in 57% of patients, associated with deterioration of LV systolic function and NYHA functional class. Biventricular pacing may reverse these adverse effects of RV pacing.

A novel two-dimensional echocardiographic image analysis system using artificial intelligence-learned pattern recognition for rapid automated ejection fraction.

OBJECTIVES: We sought to test the hypothesis that a novel 2-dimensional echocardiographic image analysis system using artificial intelligence-learned pattern recognition can rapidly and reproducibly calculate ejection fraction (EF). BACKGROUND: Echocardiographic EF by manual tracing is time consuming, and visual assessment is inherently subjective. METHODS: We studied 218 patients (72 female), including 165 with abnormal left ventricular (LV) function. Auto EF incorporated a database trained on >10,000 human EF tracings to automatically locate and track the LV endocardium from routine grayscale digital cineloops and calculate EF in 15 s. Auto EF results were independently compared with manually traced biplane Simpson's rule, visual EF, and magnetic resonance imaging (MRI) in a subset. RESULTS: Auto EF was possible in 200 (92%) of consecutive patients, of which 77% were completely automated and 23% required manual editing. Auto EF correlated well with manual EF (r = 0.98; 6% limits of agreement) and required less time per patient (48 +/- 26 s vs. 102 +/- 21 s; p < 0.01). Auto EF correlated well with visual EF by expert readers (r = 0.96; p < 0.001), but interobserver variability was greater (3.4 +/- 2.9% vs. 9.8 +/- 5.7%, respectively; p < 0.001). Visual EF was less accurate by novice readers (r = 0.82; 19% limits of agreement) and improved with trainee-operated Auto EF (r = 0.96; 7% limits of agreement). Auto EF also correlated with MRI EF (n = 21) (r = 0.95; 12% limits of agreement), but underestimated absolute volumes (r = 0.95; bias of -36 +/- 27 ml overall). CONCLUSIONS: Auto EF can automatically calculate EF similarly to results by manual biplane Simpson's rule and MRI, with less variability than visual EF, and has clinical potential.

Velocity vector imaging to quantify ventricular dyssynchrony and predict response to cardiac resynchronization therapy.

Velocity vector imaging is a novel quantitative echocardiographic technique that was applied to routine grayscale echocardiographic images of 23 patients with heart failure who underwent cardiac resynchronization therapy. The hypothesis was tested that velocity vector imaging can quantify left ventricular mechanical dyssynchrony and predict response to resynchronization therapy. Tissue velocities were determined by the automated tracking of periodic B-mode image patterns on digital cine loops from standard apical 4-chamber, 2-chamber, and long-axis views, with the user tracing the mid left ventricular wall from a single frame. Dyssynchrony was determined as the greatest opposing wall peak longitudinal systolic velocity delay from the 3 views. Responders, defined as those with >or=15% increases in the ejection fraction, had greater baseline dyssynchrony than nonresponders (opposing wall velocity delays of 131 +/- 83 vs 52 +/- 60 ms, p <0.05), and >or=75 ms predicted response with 85% sensitivity and 80% specificity when followed 8 +/- 5 months after resynchronization therapy. Baseline electrocardiographic QRS duration was not predictive in the same patients. In conclusion, echocardiographic velocity vector imaging has potential for clinical utility.

Novel speckle-tracking radial strain from routine black-and-white echocardiographic images to quantify dyssynchrony and predict response to cardiac resynchronization therapy.

BACKGROUND: Mechanical dyssynchrony is a potential means to predict response to cardiac resynchronization therapy (CRT). We hypothesized that novel echocardiographic image speckle tracking can quantify dyssynchrony and predict response to CRT. METHODS AND RESULTS: Seventy-four subjects were studied: 64 heart failure patients undergoing CRT (aged 64+/-12 years, ejection fraction 26+/-6%, QRS duration 157+/-28 ms) and 10 normal controls. Speckle tracking applied to routine midventricular short-axis images calculated radial strain from multiple circumferential points averaged to 6 standard segments. Dyssynchrony from timing of speckle-tracking peak radial strain was correlated with tissue Doppler measures in 47 subjects (r=0.94, P<0.001; 95% CI 0.90 to 0.96). The ability of baseline speckle-tracking radial dyssynchrony (time difference in peak septal wall-to-posterior wall strain > or =130 ms) to predict response to CRT was then tested. It predicted an immediate increase in stroke volume in 48 patients studied the day after CRT with 91% sensitivity and 75% specificity. In 50 patients with long-term follow-up 8+/-5 months after CRT, baseline speckle-tracking radial dyssynchrony predicted a significant increase in ejection fraction with 89% sensitivity and 83% specificity. Patients in whom left ventricular lead position was concordant with the site of latest mechanical activation by speckle-tracking radial strain had an increase in ejection fraction from baseline to a greater degree (10+/-5%) than patients with discordant lead position (6+/-5%; P<0.05). CONCLUSIONS: Speckle-tracking radial strain can quantify dyssynchrony and predict immediate and long-term response to CRT and has potential for clinical application.

Utility of echocardiographic radial strain imaging to quantify left ventricular dyssynchrony and predict acute response to cardiac resynchronization therapy.

Echocardiographic strain imaging was used to quantify radial mechanical dyssynchrony in 38 patients who underwent cardiac resynchronization therapy. Dyssynchrony, defined as the time difference of peak radial strain in the septum versus the posterior wall, was significantly greater in patients with acute hemodynamic responses, and changes in radial dyssynchrony correlated with changes in stroke volume. A > or =130-ms difference in septal versus posterior wall peak strain when combined with a favorable left ventricular lead position was strongly predictive of immediate improvement in stroke volume with resynchronization therapy (95% sensitivity, 88% specificity), regardless of electrocardiographic QRS duration.