Hisham Dokainish

Optimal Noninvasive Assessment of Left Ventricular Filling Pressures A Comparison of Tissue Doppler Echocardiography and B-Type Natriuretic Peptide in Patients With Pulmonary Artery Catheters

Background—Early transmitral velocity/tissue Doppler mitral annular early diastolic velocity (E/Ea) and B-type natriuretic peptide (BNP) have been correlated with left ventricular filling pressures, yet there are no data on how these 2 estimates of left ventricular filling pressures compare. Methods and Results—Patients admitted to intensive care underwent simultaneous tissue Doppler echocardiography, BNP measurement, and pulmonary capillary wedge pressure (PCWP) determination. The ability of mitral E/Ea and BNP to predict PCWP >15 mm Hg was assessed. Fifty patients were studied. Ln BNP had a correlation of r = 0.32 (P = 0.02) with PCWP compared with r = 0.69 (P < 0.001) between E/Ea and PCWP. E/Ea >15 was the optimal cutoff to predict PCWP >15 mm Hg (sensitivity, 86%; specificity, 88%), whereas the optimal BNP cutoff was >300 pg/mL (sensitivity, 91%; specificity, 56%). The correlation between change in PCWP and change in E/Ea at 48 hours was r = 0.87 (P = 0.003) compared with r = −0.59 (P = 0.39) for BNP. In the 36 patients with cardiac disease, E/Ea >15 (sensitivity, 92%; specificity, 91%) appeared more accurate than BNP >400 pg/mL (sensitivity, 92%; specificity, 51%), whereas in patients without cardiac disease, BNP (sensitivity, 81%; specificity, 83%) appeared more accurate than E/Ea >15 (sensitivity, 74%; specificity, 72%) for PCWP >15 mm Hg. Conclusions—In intensive care unit patients, mitral E/Ea has a better correlation than BNP with PCWP. Both BNP and mitral E/Ea have high sensitivity for PCWP >15 mm Hg; however, E/Ea appears more specific in this patient population. In patients without cardiac disease, BNP appears more accurate than E/Ea for PCWP >15 mm Hg, whereas E/Ea appears more accurate in patients with cardiac disease.

Usefulness of New Diastolic Strain and Strain Rate Indexes for the Estimation of Left Ventricular Filling Pressure

Tissue Doppler indexes of left ventricular (LV) filling pressure are prone to angulation errors and tethering and are less reliable in patients with preserved LV ejection fraction and indeterminate early peak transmitral diastolic flow (E)/mitral early diastolic velocity (Ea) (8 <E/Ea <15). Two-dimensional echocardiographic global longitudinal diastolic strain (Ds) and strain rate (DSr) were measured during peak mitral filling, and combined with E, derived new noninvasive indexes of LV filling pressure (E/Ds and E/10DSr). These indexes were compared with simultaneously invasively measured LV preatrial (pre-A) contraction pressure and E/Ea. Fifty patients were studied. Mean age was 55.9 +/- 9.9 years, 22 (43%) were women, and mean LV ejection fraction was 49.3 +/- 18.0%. Ds (R = 0.48, p <0.001) and DSr (R = 0.43, p = 0.002) correlated with invasively measured -dP/dt. Correlations between E/Ds and E/10DSr with LV pre-A pressure were R = 0.81 (p <0.001) and R = 0.80 (p <0.001) compared with R = 0.63 (p <0.001) between E/Ea and LV pre-A pressure, respectively. E/Ds > or =8 had higher sensitivity and specificity (95% and 94%, respectively; area under the curve = 0.96, p <0.0001) than E/Ea > or =15 (sensitivity 81%, specificity 75%; area under the curve = 0.85, p <0.0001) for the prediction of LV pre-A pressure > or =15 mm Hg (p = 0.01 for comparison). In patients with LV ejection fraction > or =50% and 8 <E/Ea <15, E/Ds and E/DSr were more accurate than E/Ea for determination of LV pre-A pressure. In conclusion, a novel ratio 2-dimensional echocardiographic diastolic strain ratio (E/Ds) was a better predictor of LV filling pressure than E/Ea. In patients with LV ejection fraction > or =50% or indeterminate E/Ea, both E/Ds and E/10DSr (a ratio based on global DSR) were better predictors of LV filling pressure than E/Ea.

A Randomized Cross-Over Study for Evaluation of the Effect of Image Optimization With Contrast on the Diagnostic Accuracy of Dobutamine Echocardiography in Coronary Artery Disease. The OPTIMIZE Trial

OBJECTIVES The purpose of this study was to evaluate whether the addition of a contrast agent to dobutamine stress echocardiography (DSE) improves its diagnostic accuracy for coronary artery disease (CAD) and to determine the effect of image quality on the diagnostic impact of contrast agent use in this setting. BACKGROUND Contrast agents can improve endocardial border definition. To date, however, there are no randomized trials that have evaluated the impact of contrast agent use on the accuracy of DSE. METHODS Patients referred for stress testing with dobutamine echocardiography underwent 2 DSE studies: 1 with and 1 without a contrast agent, at least 4 h apart in a randomized order and within a 24-h period. RESULTS A total of 101 patients underwent both DSE studies. Similar hemodynamics were achieved during the 2 stress testing sessions. The use of a contrast agent improved the percentage of segments adequately visualized at baseline (from 72 +/- 24% to 95 +/- 8%) and more so at peak stress (67 +/- 28% to 96 +/- 7%); both p < 0.001. Interpretation of wall motion with high confidence also increased with contrast agent use from 36% to 74% (p < 0.001). Segment visualization with the use of a contrast agent improved in all views, but was more pronounced in the apical views. In unenhanced DSE, 36% of studies were normal, 51% had ischemia, and 8% were uninterpretable-all of which became interpretable with the use of a contrast agent. When compared with angiography (n = 92; 55 patients with CAD), accurate detection of ischemia was higher with contrast-enhanced studies versus nonenhanced studies (p = 0.02). As endocardial visualization and confidence of interpretation decreased in unenhanced studies, a greater impact of the use of a contrast agent on DSE accuracy was observed (p < 0.01). CONCLUSIONS During dobutamine stress echocardiography, contrast agent administration improves endocardial visualization at rest and more so during stress, leading to a higher confidence of interpretation and greater accuracy in evaluating CAD. The lesser the endocardial border visualization, the higher the impact of contrast echocardiography on accuracy.

Hypertrophic obstructive cardiomyopathy-alcohol septal ablation vs. myectomy: a meta-analysis.

AIMS Our purpose is to conduct a meta-analysis of all published studies comparing alcohol septal ablation (ASA) and myectomy (MM) for drug refractory hypertrophic obstructive cardiomyopathy (HOCM). Alcohol septal ablation is a less invasive alternative to MM for relief of symptoms in patients with drug refractory HOCM. METHODS AND RESULTS An extensive search of PubMed identified five non-randomized studies comparing ASA and MM. Of 351 patients studied, 183 underwent ASA and 168 underwent MM. Patients undergoing ASA were older (mean age 54.4 +/- 6.3 vs. 45.0 +/- 4.4 years, P = 0.02). All patients were in New York Heart Association (NYHA) class II-IV. Baseline left ventricular outflow tract (LVOT) gradient was comparable (81.4 +/- 14.3 mmHg in ASA vs. 77.4 +/- 15.5 mmHg in MM, P = 0.2). Although resting LVOT gradient after septal reduction therapy in both groups was <20 mmHg at follow-up, patients undergoing MM had lower LVOT gradient (18.2 +/- 6.7 vs. 10.8 +/- 6.3 mmHg, P < 0.001). Patients in both groups had comparable improvement in NYHA class (1.5 +/- 0.3 in ASA vs. 1.3 +/- 0.2, P = 0.2) at follow-up. A higher percentage of patients undergoing ASA required permanent pacemaker (PPM) implantation for complete heart block (18.4 +/- 7.9 vs. 3.3 +/- 3.9%, P = 0.04). There was no significant in-hospital mortality difference between the two groups. CONCLUSION Alcohol septal ablation and MM provide significant reduction in LVOT gradient and NYHA functional class on mid-term follow-up. A higher percentage of patients required PPM after ASA. Randomized trials are needed to confirm current findings.

Tissue Doppler imaging in the evaluation of left ventricular diastolic function.

Purpose of review Describe the rationale behind, and clinical use of, tissue Doppler (TD) imaging in the assessment of left ventricular (LV) diastolic function, with a focus on recent developments. Recent findings Tissue Doppler imaging is a novel echocardiographic technique that directly measures myocardial velocities. Systolic TD measurements assess left and right ventricular myocardial contractile function. Diastolic TD values reflect myocardial relaxation, and in combination with conventional Doppler measurements, ratios (E/Ea) have been developed to estimate LV filling pressures. TD values and derived ratios have been demonstrated to be valuable in the diagnosis of elevated LV filling pressures, clinical congestive heart failure (CHF), and the prognosis of patients with cardiac disease and CHF. New TD indices have now been developed to assess myocardial relaxation and LV filling pressures, and the impact of LV systolic function on the use of TD imaging has recently been described. TD echocardiography is being used in an ever-widening group of patients for the assessment of LV diastolic function, and its correlation to, and comparison with, B-type natriuretic peptide is an active area of current investigation. Summary This review focuses on new developments in the clinical use of TD echocardiography in the evaluation of left ventricular diastolic function.

Pacemaker-Detected Atrial Fibrillation in Patients With Pacemakers: Prevalence, Predictors, and Current Use of Oral Anticoagulation

BACKGROUND Dual-chamber pacemakers frequently document atrial fibrillation (AF) in patients without symptoms. Pacemaker-detected AF is associated with a 2.5-fold increased risk of stroke, although it is not established whether oral anticoagulation reduces this risk. This study sought to determine the prevalence and predictors of pacemaker-detected AF and to document current oral anticoagulant use. METHODS A retrospective analysis included all patients from a single academic hospital who had pacemakers capable of documenting AF. Blinded evaluation of all echocardiograms conducted within 6 months of implantation was performed. RESULTS Of 445 patients, pacemaker-detected AF was present in 246 (55.3%), who were older (74.3 ± 13.7 years vs 71.7 ± 14.4, P = 0.046), more likely to have a history of clinical AF (29.7% vs 19.1%, P = 0.01), and had a larger left atrial volume index (34.4 ± 11.8 mL/m(2) vs 30.0 ± 9.9 mL/m(2), P = 0.019) than the patients without pacemaker-detected AF. Among patients without a clinical history of AF, left atrial volume index was higher among those with pacemaker-detected AF (33.7 ± 11.3 mL/m(2) vs 29.0 ± 10.1 mL/m(2), P = 0.034). Anticoagulants were used in 35.3% of patients with pacemaker-detected AF, compared with 21.6% of patients without (P < 0.05). In patients with pacemaker-detected AF, anticoagulants were used more frequently among patients who also had clinical AF (58.9%) compared with those without (23.7%, P < 0.001). CONCLUSIONS Pacemaker-detected AF occurs in 50% of pacemaker patients and is treated with anticoagulants in less than 25% of patients who do not have a history of clinical AF. Clinical trials are needed to determine the role of anticoagulation in this population.

Assessment of Left Ventricular Systolic Function Using Echocardiography in Patients With Preserved Ejection Fraction and Elevated Diastolic Pressures

There is controversy regarding the nature of systolic function in patients with elevated filling pressure and preserved left ventricular (LV) ejection fraction. In this study, tissue Doppler variables and 2-dimensional echocardiographic systolic strain (SS) and systolic strain rate (SSr) were measured in patients who underwent cardiac catheterization to determine correlations with invasively measured LV end-diastolic pressure (LVEDP), dP/dt, and LV mass. Forty patients were studied. Their mean age was 55.9+/-9.9 years, and their mean LV ejection fraction was 59.8+/-5.2%. Tissue Doppler systolic annular velocity (5.4+/-1.1 vs 6.4+/-1.0 cm/s, p=0.04), SS (13.4+/-3.7% vs 18.8+/-2.3%, p <0.001), and SSr (0.73+/-0.17 vs 0.98+/-0.14 s(-1), p <0.001) were significantly lower in patients with LVEDP >20 mm Hg compared with those with LVEDP <20 mm Hg. Tissue Doppler systolic velocity, SSr, and SS were correlated with LV mass (R=0.58, R=0.57, and R=0.52, respectively, all p values <0.001) and with LVEDP (R=0.49, p=0.002; R=0.79, p<0.001; and R=0.70, p<0.001, respectively). However, dP/dt was not significantly different between patients with LVEDP >20 mm Hg and those with LVEDP <20 mm Hg (1,387+/-520 vs 1,495+/-594 mm Hg/s, respectively, p=0.55) and was not correlated with LV mass (R=0.18, p=0.25). The optimum cut-off values for LVEDP >20 mm Hg were SSr <0.85 s(-1) (area under the curve 0.88, p<0.001, positive predictive value 89%, negative predictive value 86%) and SS<16% (area under the curve 0.84, p=0.002, positive predictive value 88%, negative predictive value 79%). In conclusion, as opposed to invasively measured dP/dt, tissue Doppler systolic velocity and 2-dimensional echocardiographic SS and SSr are significantly depressed in patients with preserved LV ejection fraction and LVEDP >20 mm Hg, suggesting that systolic abnormalities are present in at least some of these patients. These differences are likely because invasively measured dP/dt and these echocardiographic variables measure different systolic properties in patients with preserved LV ejection fraction.

Accelerated care versus standard care among patients with hip fracture: the HIP ATTACK pilot trial

Background: A hip fracture causes bleeding, pain and immobility, and initiates inflammatory, hypercoagulable, catabolic and stress states. Accelerated surgery may improve outcomes by reducing the duration of these states and immobility. We undertook a pilot trial to determine the feasibility of a trial comparing accelerated care (i.e., rapid medical clearance and surgery) and standard care among patients with a hip fracture. Methods: Patients aged 45 years or older who, during weekday, daytime working hours, received a diagnosis of a hip fracture requiring surgery were randomly assigned to receive accelerated or standard care. Our feasibility outcomes included the proportion of eligible patients randomly assigned, completeness of follow-up and timelines of accelerated surgery. The main clinical outcome, assessed by data collectors and adjudicators who were unaware of study group allocations, was a major perioperative complication (i.e., a composite of death, preoperative myocardial infarction, myocardial injury after noncardiac surgery, pulmonary embolism, pneumonia, stroke, and life-threatening or major bleeding) within 30 days of randomization. Results: Of patients eligible for inclusion, 80% consented and were randomly assigned to groups (30 to accelerated care and 30 to standard care) at 2 centres in Canada and 1 centre in India. All patients completed 30-day follow-up. The median time from diagnosis to surgery was 6.0 hours in the accelerated care group and 24.2 hours in the standard care group (p < 0.001). A major perioperative complication occurred in 9 (30%) of the patients in the accelerated care group and 14 (47%) of the patients in the standard care group (hazard ratio 0.60, 95% confidence interval 0.26–1.39). Interpretation: These results show the feasibility of a trial comparing accelerated and standard care among patients with hip fracture and support a definitive trial. Trial registration: ClinicalTrials.gov, no. NCT01344343.

Subclinical Atrial Fibrillation in Older Patients.

Background: Long-term continuous electrocardiographic monitoring shows a substantial prevalence of asymptomatic, subclinical atrial fibrillation (SCAF) in patients with pacemakers and patients with cryptogenic stroke. Whether SCAF is also common in other patients without these conditions is unknown. Methods: We implanted subcutaneous electrocardiographic monitors (St. Jude CONFIRM-AF) in patients ≥65 years of age attending cardiovascular or neurology outpatient clinics if they had no history of atrial fibrillation but had any of the following: CHA2DS2-VASc score of ≥2, sleep apnea, or body mass index >30 kg/m2. Eligibility also required either left atrial enlargement (≥4.4 cm or volume ≥58 mL) or increased (≥290 pg/mL) serum NT-proBNP (N-terminal pro–B-type natriuretic peptide). Patients were monitored for SCAF lasting ≥5 minutes. Results: Two hundred fifty-six patients were followed up for 16.3±3.8 months. Baseline age was 74±6 years; mean CHA2DS2-VASc score was 4.1±1.4; left atrial diameter averaged 4.7±0.8 cm; and 48% had a prior stroke, transient ischemic attack, or systemic embolism. SCAF ≥5 minutes was detected in 90 patients (detection rate, 34.4%/y; 95% confidence interval [CI], 27.7–42.3). Baseline predictors of SCAF were increased age (hazard ratio [HR] per decade, 1.55; 95% CI, 1.11–2.15), left atrial dimension (HR per centimeter diameter, 1.43; 95% CI, 1.09–1.86), and blood pressure (HR per 10 mm Hg, 0.87; 95% CI, 0.78–0.98), but not prior stroke. The rate of occurrence of SCAF in those with a history of stroke, systemic embolism, or transient ischemic attack was 39.4%/y versus 30.3%/y without (P=0.32). The cumulative SCAF detection rate was higher (51.9%/y) in those with left atrial volume above the median value of 73.5 mL. Conclusions: SCAF is frequently detected by continuous electrocardiographic monitoring in older patients without a history of atrial fibrillation who are attending outpatient cardiology and neurology clinics. Its clinical significance is unclear. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01694394.

Speckle Strain Echocardiography Predicts Outcome in Patients with Heart Failure with both Depressed and Preserved Left Ventricular Ejection Fraction

While speckle imaging has been shown to predict outcome in patients with heart failure (HF), it remains unclear whether speckle strain predicts outcome in patients with HF with preserved ejection fraction (HFPEF).