Radiation Exposure to the Interventional Echocardiographers and Sonographers: A Call to Action.

Interventional echocardiography is a rapidly growing field within the disciplines of cardiology and anesthesiology, with the rise of advanced transcatheter procedures making skilled imagers more important than ever. However, these procedures also involve frequent manipulation of the transesophageal echocardiography probe, which means interventional echocardiographers (IEs) are at risk of long-term occupational radiation exposure. Studies have shown that radiation exposure is linked to various health issues, including cancer, cataracts, hypertension, hyperlipidemia, endothelial dysfunction, vascular aging, and early atherosclerosis. While there is increasing awareness of the occupational radiation dose limits and the need for better shielding methods, the importance of radiation safety for the IE is still not sufficiently prioritized in most cardiac catheterization laboratories/hybrid operating rooms. This is partly due to a paucity of studies looking at long-term radiation exposure to the IE, as this field is newer than that of interventional cardiologists.

Observed to expected 30-day mortality as a benchmark for transcatheter aortic valve replacement.

OBJECTIVE: The observed-to-expected 30-day mortality ratio (O:E ratio) is a standard metric by which transcatheter aortic valve replacement (TAVR) trials have been evaluated. Early TAVR trials consistently demonstrated O:E ratio less than 0.6 after TAVR when based on the Society for Thoracic Surgery Predicted Risk of Mortality (STS-PROM) for surgical aortic valve replacement. Recent published results from the Transcatheter Valve Therapy (TVT) Registry have demonstrated O:E ratios of 1.0. We evaluated our own O:E ratios for TAVR to investigate this discordance. METHODS: Data were collected prospectively for TAVR patients from 2008 through 2015 (N = 546) and were reviewed retrospectively. The observed mortality and STS-PROM were calculated to formulate O:E ratios and were compared over a variety of subgroups. RESULTS: Overall, the O:E ratio for 30-day mortality was 0.4 and significantly less than 1 (P < .001; 95% confidence interval, 0.25-0.63). The O:E ratio relationship remained less than 0.5 for patients with low (STS-PROM < 4), moderate (STS-PROM = 4-8) and high risk (STS-PROM > 8). The O:E ratio was significantly higher for transapical patients (O:E ratio = 0.8) when compared with transfemoral patients (O:E ratio = 0.2). Lastly, O:E ratios for both commercial (O:E ratio = 0.5) and research (O:E ratio = 0.3) patients were similar (P = .337), and both were significantly less than 1 (P = .007 and P < .001, respectively). CONCLUSIONS: The STS-PROM consistently overestimated 30-day mortality after TAVR. Achieving an O:E ratio less than 0.6 may be a realistic goal for all TAVR programs. While an accurate and specific risk calculator for 30-day mortality after TAVR remains to be established, our data suggest that current TVT results are not acceptable for commercial TAVR and that programs with an O:E ratio greater than 0.6, based on the STS-PROM, should reevaluate internal processes to improve their results.

Learning Alternative Access Approaches for Transcatheter Aortic Valve Replacement: Implications for New Transcatheter Aortic Valve Replacement Centers.

BACKGROUND: Smaller transcatheter aortic valve replacement (TAVR) delivery systems have increased the number of patients eligible for transfemoral procedures while decreasing the need for transaortic (TAo) or transapical (TA) access. As a result, newer TAVR centers are likely to have less exposure to these alternative access techniques, making it harder to achieve proficiency. The purpose of this study was to evaluate the learning curve for TAVR approaches and compare perioperative outcomes. METHODS: From January 2008 to December 2014, 400 patients underwent TAVR (transfemoral, n = 179; TA, n = 120; and TAo, n = 101)). Learning curves were constructed using metrics of contrast utilization, procedural, and fluoroscopy times. Outcomes during the learning curve were compared with after proficiency was achieved. RESULTS: Depending on the metric, learning curves for all three routes differed slightly but all demonstrated proficiency by the 50th case. There were no significant differences in procedural times whereas improvements in contrast use were most notable for TA (69 ± 40 mL versus 50 ± 23 mL, p = 0.002). For both TA and TAo, fewer patients received transfusions once proficiency was reached (62% versus 34%, p = 0.003, and 42% versus 14%, p = 0.002, respectively). No differences in 30-day or 1-year mortality were seen before or after proficiency was reached for any approach. CONCLUSIONS: The learning curves for TA and TAo are distinct but technical proficiency begins to develop by 25 cases and becomes complete by 50 cases for both approaches. Given the relatively low volume of alternative access, achieving technical proficiency may take significant time. However, technical proficiency had no effect on 30-day or 1-year mortality for any access approach.

Delirium after surgical and transcatheter aortic valve replacement is associated with increased mortality.

OBJECTIVE: The purpose of this study was to determine the incidence and clinical significance of postoperative delirium (PD) in patients with aortic stenosis undergoing surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR). METHOD: Between 2010 and 2013, 427 patients underwent TAVR (n = 168) or SAVR (n = 259) and were screened for PD using the Confusion Assessment Method for the Intensive Care Unit. The incidence of PD in both treatment groups was determined and its association with morbidity and mortality was retrospectively compared. RESULTS: PD occurred in 135 patients (32%) with a similar incidence between SAVR (33% [86 out of 259]) and TAVR (29% [49 out of 168]) (P = .40). TAVR by transfemoral approach had the lowest incidence of PD compared with SAVR (18% vs 33%; P = .025) or TAVR when performed by alternative access techniques (18% vs 35%; P = .02). Delirium was associated with longer initial intensive care unit stay (70 vs 27 hours), intensive care unit readmission (10% [14 out of 135] vs 2% [6 out of 292]), and longer hospital stay (8 vs 6 days) (P < .001 for all). PD was associated with increased mortality at 30 days (7% vs 1%; P < .001) and 1 year (21% vs 8%; P < .001). After multivariable adjustment, PD remained associated with increased 1-year mortality (hazard ratio, 3.02; 95% confidence interval, 1.75-5.23; P < .001). There was no interaction between PD and aortic valve replacement approach with respect to 1-year mortality (P = .12). Among propensity-matched patients (n = 170), SAVR-treated patients had a higher incidence of PD than TAVR-treated patients (51% vs 29%; P = .004). CONCLUSIONS: PD occurs commonly after SAVR and TAVR and is associated with increased morbidity and mortality. Given the high incidence of PD and its associated adverse outcomes, further studies are needed to minimize PD and potentially improve patient outcomes.

Preoperative pulmonary function tests predict mortality after surgical or transcatheter aortic valve replacement.

OBJECTIVES: To determine the role of preoperative pulmonary function tests (PFTs) in patients with aortic stenosis (AS) evaluated for aortic valve replacement (AVR), and to evaluate the association between lung disease and mortality in specific subgroups. METHODS: Between 2008 and 2013, 535 patients with preoperative PFTs underwent AVR (transcatheter AVR [TAVR], n = 246; surgical AVR [SAVR], n = 289). The severity of lung disease determined by the Society of Thoracic Surgeons (STS) definition was evaluated in those with and without a clinical suspicion for lung disease (smoking, inhaled steroids/bronchodilators, or home oxygen). The association between lung disease and 1-year mortality was evaluated. RESULTS: Of the 186 patients (35%) without suspected lung disease, 39 (21%) had moderate/severe lung disease by PFT analysis. Among all patients, 1-year mortality was 12% in those with no lung disease, 17% in those with no mild lung disease, 22% in those with moderate lung disease, and 31% in those with severe lung disease (P < .001, log-rank test). After adjustment, moderate/severe lung disease was associated with increased 1-year mortality (adjusted hazard ratio, 2.07; 95% confidence interval, 1.30-3.29; P = .002); this association was not altered by smoking history, suspicion of lung disease, New York Heart Association class, or AVR type (interaction P value nonsignificant for all). CONCLUSIONS: In patients with AS evaluated for AVR, the STS risk score is significantly influenced by the severity of lung disease, which is determined predominantly by PFT results. Even when lung disease is not suspected, PFTs are abnormal in many patients undergoing AVR. Moderate/severe lung disease, diagnosed predominantly by PFTs, is an independent predictor of mortality after SAVR or TAVR. Collectively, these findings suggest that PFTs should be a routine part of the risk stratification of patients considered for AVR.

Visual Estimation of the Severity of Aortic Stenosis and the Calcium Burden by 2-Dimensional Echocardiography: Is It Reliable?

OBJECTIVES: Guidelines have recommended aortic valve surgery in asymptomatic patients with severe aortic stenosis and a large aortic valve calcium burden. The purpose of this study was to determine whether visual assessment of aortic valve calcium and stenosis severity are reliable based on 2-dimensional echocardiography alone. METHODS: We prospectively enrolled 68 patients with aortic stenosis and compared them with 30 control participants without aortic stenosis. All had aortic valve calcium score assessment by computed tomography. In a random order, 2-dimensional images without hemodynamic data were independently reviewed by 2 level 3-trained echocardiographers, who then classified these patients into categories based on aortic valve calcium and stenosis severity. RESULTS: The 68 patients (mean age ± SD, 74 ± 10 years) were classified as having mild (n = 28), moderate (n = 22), and severe (n = 18) aortic stenosis. When the observers were asked to grade the degree of valve calcification, the agreement between them was poor (κ = 0.33-0.39). The visual ability to determine stenosis severity compared with Doppler echocardiography had high specificity (81% and 88% for observers 1 and 2). However, sensitivity was unacceptably low (56%-67%), and the positive predictive value was poor (44%-50%). Agreement was fair (κ= 0.58-0.69) between the observers for determining severe stenosis. CONCLUSIONS: Our results suggest that visual assessment of aortic valve calcium has high interobserver variability; the visual ability to determine severe aortic stenosis has low sensitivity but high specificity. Our results may have important implications for treatment of patients with aortic stenosis and guiding the use of handheld echocardiography. Further research with larger cohorts is needed to validate the variability, sensitivity, and specificity reported in our study.

Percutaneous closure of perivalvular mitral regurgitation: how should the interventionalists and the echocardiographers communicate?

There is considerable interest in percutaneous closure of perivalvular leaks without the need for repeat surgery. Successful percutaneous closure of these defects requires extensive planning and coordination before and during the procedure. However, there is no standardized description of valve pathology in the presence of a prosthetic valve, which adds to the challenge of communication. Transesophageal echocardiography is ideally suited to guide percutaneous mitral valve procedures, because of the proximity of the mitral valve to the esophagus. Successful percutaneous procedures of the mitral valve require teamwork. Both the interventionalist and the echocardiographer must have great familiarity with mitral valve anatomy, structure, and function, and they must know how to effectively communicate with each other. The authors review the relevant periprocedural mapping of the mitral valve and provide guidance to echocardiographers and interventionalists on effective ways to communicate during percutaneous perivalvular mitral leak closures to accomplish a successful outcome.

Two and three dimensional echocardiography for pre-operative assessment of mitral valve regurgitation.

Mitral regurgitation may develop when the leaflets or any other portion of the apparatus becomes abnormal. As the repair techniques for mitral valve disease evolved, so has the need for detailed and accurate imaging of the mitral valve prior to surgery in order to better define the mechanism of valve dysfunction and the severity of regurgitation. In patients with significant mitral valve disease who require surgical intervention, multiplane transesophageal echocardiogram (TEE) is invaluable for surgical planning. However, a comprehensive TEE in a patient with complex mitral valve disease requires great experience and skill. There is evidence to suggest that 3D echocardiography can overcome some of the limitations of 2D multiplane TEE and thus is crucial in evaluation of patients undergoing mitral valve surgery. In the following sections, we review some of the crucial 2D and 3D echo images necessary for evaluation of MR based on the Carpentier classification.

Worsening left ventricular apical peak strain early after right ventricular pacing.

We aimed to determine the effect of short-term right ventricle pacing (RV) on left ventricle (LV) mechanics using speckle tracking analysis. Conventional echocardiography and two-dimensional strain imaging was studied in 38 patients, mean age 81.6 ± 7.0, that had undergone pacemaker placement and were greater than 90% ventricularly paced. Mean duration of 24 months of RV pacing resulted in a significant decline in: LV apical diastolic rotational velocities (-59.0 ± -38.9 °/s to -28.0 ± -11.5 °/s, p 0.02), peak strain in the LV apical septal wall (-15.6 ± 8.5 to -13.5 ± 7.6, p 0.02), peak strain in LV apical lateral wall (-13.4 ± 8.9 to -11.4 ± 7.3, p 0.02). Thus, with only 24 months of RV pacing, there was a significant decline in peak strain of the LV apex and in apical diastolic rotational velocity that could account for eventual decline in left ventricular function.

Effect of mitral inflow pattern on diagnosis of severe mitral regurgitation in patients with chronic organic mitral regurgitation.

BACKGROUND: To determine sensitivity and specificity of E wave velocity in patients with severe chronic organic mitral regurgitation (MR) and normal left ventricular ejection fraction (EF) and to evaluate prevalence of A wave dominance in patients with severe MR. METHODS: We compared 35 patients with quantified severe, chronic, quantified, organic MR due to flail/prolapsed leaflets who had reparative surgery with 35 age-matched control subjects. EXCLUSION CRITERIA: EF < 60%, atrial fibrillation, and more than mild aortic regurgitation. RESULTS: Mean [standard deviation (SD)] age [70 (8) years vs. 69 (8) years; p = 0.94] and mean (SD) EF [66% (6%) vs. 65% (4%); p = 0.43] were not different between the two groups. Mean (SD) E wave velocity was greater in case patients than control subjects [1.2 (0.3) m/sec vs. 0.7 (0.15) m/sec; p < 0.001]. However, E wave velocity of 1.2 m/sec had a sensitivity of only 57% [95% confidence interval (CI), 41-7 and a specificity of 100% (95% CI, 90-100%) in identifying severe MR. E wave velocity of 0.9 m/sec had a more optimal combined sensitivity (89%; 95% CI, 74-95%) and specificity (86%; 95% CI, 71-94%). A wave dominance was seen in 18% of case patients and 66% of control subjects (p < 0.001). CONCLUSION: E wave velocity of 1.2 m/sec is specific not sensitive for severe organic MR; E wave velocity of 0.9 m/sec has better sensitivity and specificity. A wave dominance pattern alone cannot exclude patients with severe organic MR. Our findings highlight the importance of a comprehensive echocardiographic exam rather than relying on a few Doppler parameters in diagnosing MR.

Left ventricular assist devices: physiologic assessment using echocardiography for management and optimization.

Left ventricular assist devices (LVAD) are being deployed increasingly in patients with severe left ventricular dysfunction and medically refractory congestive heart failure of any etiology. The United States Food and Drug Administration (FDA) recently approved the use of the Thoratec Heartmate II (Thoratec Corporation, Pleasanton, CA, USA) for outpatient use. Echocardiography is fundamental during each stage of patient management, pre-LVAD placement, during LVAD placement, for postoperative LVAD optimization and long-term follow-up. We present a pragmatic and systematic echocardiographic approach that serves as a guide for the management of left ventricular assist devices.