Search

Up to a quarter of vascular complications during transcatheter aortic valve implantation (TAVI) result from secondary access via the femoral artery (FA). The radial artery (RA) is increasingly used as an alternative to the FA for secondary access in TAVI. Limited data exist on the outcomes of RA secondary access versus FA secondary access. We therefore conducted a systematic review and meta-analysis comparing secondary access sites. PubMed, EMBASE, Scopus, Cochrane library and CINAHL were searched systematically for studies comparing RA and FA as secondary access sites for TAVI. Primary outcomes of interest were vascular complications and major bleeding. Secondary outcomes included all-cause mortality, stroke and myocardial infarction (MI). Risk ratio (RR), standardized mean difference and corresponding 95% confidence intervals (CI) were calculated using a random effects model. Six observational studies comprising 6,373 patients (RA: 1,514, FA: 4,859) met inclusion criteria. Secondary access was utilized for aortography during valve deployment and to manage primary access site complications. Procedural characteristics were similar in both groups. RA was associated with a lower risk of major bleeding (RR: 0.51, 95% CI: 0.40 to 0.64, p <0.00001). No statistically significant difference was observed in the incidence of overall vascular complications, however, the risk of major vascular complications was lower with RA (RR: 0.45, 95% CI: 0.32 to 0.63, p <0.00001). The incidence of stroke and all-cause mortality was lower in RA, whereas no difference was observed in the risk of MI. In conclusion, our meta-analysis suggests that RA secondary access is associated with better outcomes for TAVI than FA., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Because left atrial (LA) volume plays a critical role in determining cardiovascular outcomes, it was hypothesized that this might be related to the distensibility of the left atrium and how this relates to left ventricular filling pressure (LVFP). Echocardiographic estimates of LVFP were compared to cardiac catheterization measurements in 521 consecutive patients with acute myocardial infarction and correlated with short- and long-term outcomes. Receiver-operating characteristic curve analysis was performed to investigate the sensitivity and specificity of echocardiographic parameters for predicting elevated LVFP (> 15 mm Hg). LA distensibility was calculated as (maximal volume - minimal volume) × 100%/minimal volume(.) and was found to be logarithmically associated with LVFP (p < 0.0001). LA distensibility was superior to mitral E/annular Em for identifying increased LVFP (area under the receiver-operating characteristic curve 0.92 vs 0.78). A total of 44 patients died during hospitalization, and 89 patients had died or experienced heart failure requiring rehospitalization at 12-month follow-up. In a multivariate Cox regression model, LA distensibility was an independent predictor of in-hospital mortality (hazard ratio 2.373 for LA distensibility ≤ 60%, p = 0.026), while LA volume was an independent prognostic factor of 1-year death or heart failure (hazard ratio 2.266 for LA volume ≥ 34 ml/m², p = 0.007). In conclusion, LA distensibility accurately identifies patients with increased LVFP after acute myocardial infarction and is an independent predictor of in-hospital mortality., (Copyright © 2011 Elsevier Inc. All rights reserved.)

In a pilot study of 27 patients, those who presented with chest pain underwent 2 dobutamine stress echocardiographic studies, 1 with high mechanical index harmonic imaging to analyze wall motion without contrast and 1 with real-time low mechanical index perfusion imaging with intravenous Optison to assess myocardial perfusion and wall motion. All patients then underwent quantitative coronary angiography. Two independent reviewers demonstrated an improvement in sensitivity when analyzing myocardial perfusion. In the 21 patients who had significant coronary stenoses, 14 had abnormal myocardial perfusion detected at peak stress and 7 had abnormal wall motion detected by standard dobutamine stress echocardiography. There was decreased specificity with perfusion imaging by 1 reviewer. The addition of real-time perfusion imaging after intravenous contrast during dobutamine stress echocardiography has the potential to improve detection of coronary artery disease.

Myocardial contrast echocardiography has the potential to accurately detect functionally significant coronary artery disease during pharmacologic stress testing. Different low-mechanical index modalities, including triggering replenishment imaging (TRI) and real-time imaging (RTI), are currently used to identify myocardial perfusion defects. We compared the ability of TRI with that of RTI for detecting and localizing perfusion abnormalities. Thirty-six patients (62 +/- 14 years old, 15 men) underwent single-photon emission computed tomography (SPECT) with technetium-99m sestamibi and myocardial contrast echocardiography at baseline and after infusion of 0.56 mg/kg of dipyridamole. Sixteen of these patients also underwent quantitative angiography. Contrast-enhanced images were obtained in 4-, 3-, and 2-chamber views after intravenous bolus injections of lipid-encapsulated microbubbles (0.1 ml of Definity). A myocardial perfusion defect was defined by myocardial contrast echocardiography as a delay of >2 seconds in contrast replenishment after high-mechanical index flash impulse. The myocardial segments were divided into 3 major coronary territories. There was agreement in detecting perfusion defects between SPECT and TRI in 26 patients (72%, kappa = 0.46) and between SPECT and RTI in 27 patients (75%, kappa = 0.50). Agreements between myocardial contrast echocardiography and SPECT for localizing coronary territories with perfusion defects were 81% for TRI (kappa = 0.43) and 85% for RTI (kappa = 0.61). Accuracy of RTI for detecting >50% diameter stenoses by quantitative angiography was 79%, that of TRI was 71%, and that of SPECT was 65%. These data indicate that the different low-mechanical index imaging schemes are equivalent to radionuclide SPECT in accurately detecting diseased coronary artery territories during vasodilator stress.

Papillary muscle (PM) function is vital to mitral valve competence. However, quantitative assessment of the function is difficult due to the complexity of the mitral apparatus. We hypothesized that myocardial velocity gradient (MVG) could be applied to assess PM function. We studied MVG-PM in 123 patients with left ventricular dysfunction (ejection fraction <40%) and 123 normal subjects throughout a systolic phase. MVG-PM in normal subjects was significantly higher than in patients with left ventricular dysfunction (3.6/s vs 1.4/s, p <0.001). MVG-PM reached its peak at early systole and correlated well with PM thickening (r = 0.89). MVG-PM in patients with left ventricular dysfunction correlated with the severity of apical tenting of the mitral valve (y = 0.8x - 0.07, r = 0.72). Patients with lower MVG-PM tended to have less severe mitral regurgitation (y = 0.03x + 0.3, r = 0.83). PM contractility can be quantitatively assessed by calculating the MVG derived from tissue Doppler imaging. PM dysfunction, indicated by lower MVG-PM, decreased mitral leaflet tethering, thus paradoxically decreasing mitral regurgitation severity. MVG is a useful tool in determining the role of PM in functional mitral regurgitation.

Coronary artery disease is the underlying etiology of left ventricular dysfunction and arrhythmias in most patients who receive implantable cardioverter defibrillators (ICDs). The aim of this study was to assess the safety and feasibility of dobutamine stress echocardiography (DSE) in patients with an ICD. DSE (dobutamine up to 50 microg/kg/min, atropine up to 2 mg) was performed in 87 patients with an ICD and known or suspected coronary artery disease. The ICD was inactivated before the stress test and reactivated after the study; no serious complications occurred. DSE is a safe and feasible method for evaluating myocardial ischemia in patients with an ICD.

Intravenous injections or infusions of perfluorocarbon-exposed sonicated dextrose albumin microbubbles were given 2.4 +/- 1.6 days following acute myocardial infarction to 45 consecutive patients. Patients were divided into 3 groups: patients with Thrombolysis In Myocardial Infarction (TIMI) grade 3 angiographic flow but persistent myocardial contrast defects by echocardiography (no reflow), patients with TIMI 3 flow and myocardial contrast enhancement (reflow), and patients with TIMI grade 0 to 2 flow in the infarct vessel. Thirty-five patients had TIMI 3 flow at the time of contrast study. Of these, 25 had evidence of reflow with intravenous contrast, whereas 10 (29%) still had contrast defects. At follow-up, end-systolic volume index decreased significantly in patients who exhibited reflow (21 +/- 8 ml/m2 at baseline to 18 +/- 8 ml/m2 at follow-up; p = 0.04), whereas those with no reflow had a significant increase (26 +/- 9 ml/m2 at baseline to 32 +/- 9 ml/m2 at follow-up; p = 0.006). A persistent contrast defect in the infarct zone demonstrated with intravenous ultrasound contrast following restoration of TIMI grade 3 flow in the infarct vessel identified patients likely to have deterioration in both regional and global systolic function.

These IVUS-derived data indicate that failure of compensatory dilation is an important factor in the development of clinically and angiographically significant coronary artery disease independent of plaque burden. We observed an actual reduction in total vessel area at the most stenotic site in coronary arteries that had a quantitatively significant angiographic lesion.

Myocardial contrast echocardiography has revealed that successful coronary angioplasty results in an immediate decrease in the amount of collateral blood flow to the perfusion bed supplied by the dilated vessel. This information could potentially be used with pharmacologic stress in the catheterization laboratory to also assess the improvement in coronary flow reserve after angioplasty. The immediate changes in area under the time intensity curve produced by a 1 ml slow injection of sonicated albumin immediately proximal to a stenosis before and after 14 angiographically successful angioplasties was studied in 12 patients. Area under the curve was assessed before and after an 8 mg selective injection of papaverine. The changes in area under the curve were correlated with percent improvement in epicardial area stenosis. Visually successful angioplasty resulted in > 30% improvement in area under the curve after papaverine in 9 of 14 studies. There was a significant correlation between improvement in area under the curve after papaverine and percent improvement in epicardial area stenosis (r = 0.75; p < 0.01). No patient had left ventricular wall motion abnormalities after papaverine before or after angioplasty. These changes suggest that quantitatively successful angioplasty results in decreased collateral blood flow to the involved myocardium during pharmacologic stress. These improvements in coronary flow reserve cannot be predicted by visual analysis of angioplasty results.

This study further defines the mechanism of blood flow during closed-chest compression using transesophageal Doppler echocardiography. Although the echocardiographic demonstration of mitral valve closure during closed-chest compression has been used as evidence of direct cardiac compression, mitral valve closure has also been documented to occur during resuscitation by selectively increasing intrathoracic pressure. Transesophageal Doppler echocardiography was used to assess mitral valve position and flow in 17 adult patients undergoing cardiopulmonary resuscitation with a mechanical piston compression device. Left and right ventricular fractional shortening, mitral valve position with chest compression, timing and magnitude of transmitral flow, and anteroposterior chest diameter were recorded. In 12 patients (group I), the mitral valve closed during the down-stroke of chest compression; in the remaining 5 (group II), it opened further. Peak transmitral flow occurred during the release phase and was significantly higher (p < 0.05) in group I (39.5 +/- 9.3 cm/s) than the peak flow in group II (21.3 +/- 5.9 cm/s), which occurred during the downstroke of chest compression. Left ventricular fractional shortening inversely correlated (r = -0.68; p = 0.02) with the anteroposterior chest diameter, but did not correlate with peak transmitral flow (r = 0.34; p = not significant). It is concluded that the mitral valve closes during the downstroke of chest compression in most adult patients during resuscitation. The absence of a relation between mitral valve flow and left ventricular fractional shortening supports the hypothesis that other factors such as nonuniform increases in intrathoracic pressure cause the mitral valve to open or close during chest compression.

Dynamically trained athletes develop increased left ventricular (LV) wall mass. To determine whether this increased wall mass impaired characteristics of LV diastolic filling, serial Doppler echocardiograms were obtained from 10 trained athletes (mean age 21 years) at rest, during supine graded bicycle exercise and during recovery at heart rates of 80, 120 and 140 beats/min, respectively. Similar studies were obtained in 10 age-matched control subjects. Studies at rest showed significant increases in athletes in LV end-diastolic dimension and indexed LV wall mass. Differences in peak filling rates and in normalized peak lengthening rates between athletes and control subjects were seen at heart rates of 140 beats/min during exercise and recovery. Differences in Doppler-derived variables between athletes and control subjects were seen in total time-velocity integral, early peak filling velocity and E/A ratio. In athletes, time-velocity integral was increased during recovery at heart rates of 120 beats/min and 80 beats/min, early peak filling velocity was increased during exercise at 120 beats/min and during recovery at 120 beats/min and 80 beats/min, and E/A ratio was higher at all heart rates during both exercise and recovery. Although no significant differences were found in LV diastolic filling indexes at rest, a significant enhancement was found in these parameters in dynamically trained athletes during exercise, particularly at higher levels of dynamic exercise.