Preeti Kansal

Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study

Objectives: Ejection fraction (EF) and end-systolic volume index (ESVI) are established predictors of outcomes following ST-segment elevation myocardial infarction (STEMI). We sought to assess the relative impact of infarct size, EF and ESVI on clinical outcomes and left ventricular (LV) remodelling. Design: Prospective cohort study. Setting: Academic hospital in Chicago, USA. Patients: 122 patients with STEMI following acute percutaneous reperfusion. Main outcome measures: Death, recurrent myocardial infarction (MI) and heart failure. Methods: Cardiac magnetic resonance imaging was obtained within 1 week following STEMI in 122 subjects. ESVI, EF and infarct size were tested for the association with outcomes over 2 years in 113 subjects, and a repeat study was obtained 4 months later to assess LV remodelling in 91 subjects. Results: Acute infarct size correlated linearly with the initial ESVI (r = 0.69, p<0.001), end-diastolic volume index (EDVI) (r = 0.42, p<0.001) and EF (r = −0.75, p<0.001). All were independently associated with outcomes (one death, one recurrent MI and 16 heart failure admissions). However, infarct size was the only significant predictor of adverse outcomes (p<0.05) by multivariate analysis. The smallest infarct size tertile had an increased EF (49% (SD 8%) to 53% (6%); p = 0.002) and unchanged EDVI (p = 0.7). In contrast, subjects with the largest infarct tertile also had improved EF (32% (9%) to 36% (11%); p = 0.002) at the expense of a dramatic increase in EDVI (86 (19) to 95 (21) ml/m2; p = 0.005). Conclusions: Infarct size, EF and ESVI can predict the development of future cardiac events. Acute infarct size, which is independent of LV stunning and loading, directly relates to LV remodelling and is a stronger predictor of future events than measures of LV systolic performance.

Bicuspid Aortic Cusp Fusion Morphology Alters Aortic Three-Dimensional Outflow Patterns, Wall Shear Stress, and Expression of Aortopathy

Background— Aortic 3-dimensional blood flow was analyzed to investigate altered ascending aorta (AAo) hemodynamics in bicuspid aortic valve (BAV) patients and its association with differences in cusp fusion patterns (right-left, RL versus right-noncoronary, RN) and expression of aortopathy. Methods and Results— Four-dimensional flow MRI measured in vivo 3-dimensional blood flow in the aorta of 75 subjects: BAV patients with aortic dilatation stratified by leaflet fusion pattern (n=15 RL-BAV, mid AAo diameter=39.9±4.4 mm; n=15 RN-BAV, 39.6±7.2 mm); aorta size controls with tricuspid aortic valves (n=30, 41.0±4.4 mm); healthy volunteers (n=15, 24.9±3.0 mm). Aortopathy type (0–3), systolic flow angle, flow displacement, and regional wall shear stress were determined for all subjects. Eccentric outflow jet patterns in BAV patients resulted in elevated regional wall shear stress (P<0.0125) at the right-anterior walls for RL-BAV and right-posterior walls for RN-BAV in comparison with aorta size controls. Dilatation of the aortic root only (type 1) or involving the entire AAo and arch (type 3) was found in the majority of RN-BAV patients (87%) but was mostly absent for RL-BAV patients (87% type 2). Differences in aortopathy type between RL-BAV and RN-BAV patients were associated with altered flow displacement in the proximal and mid AAo for type 1 (42%–81% decrease versus type 2) and distal AAo for type 3 (33%–39% increase versus type 2). Conclusions— The presence and type of BAV fusion was associated with changes in regional wall shear stress distribution, systolic flow eccentricity, and expression of BAV aortopathy. Hemodynamic markers suggest a physiological mechanism by which the valve morphology phenotype can influence phenotypes of BAV aortopathy.

Midterm Benefits of Preoperative Statin Therapy in Patients Undergoing Isolated Valve Surgery

BACKGROUND Recent data have suggested that statins are associated with reduced early mortality and cardiovascular events after valvular heart surgery. The midterm effects of preoperative statin therapy in the setting of valvular heart surgery are presently unclear. METHODS All patients (n=2,120) who underwent a valvular procedure between April 2004 and April 2010 were identified. Patients undergoing concomitant coronary artery bypass graft surgery were excluded. Two patient groups were studied: those who received preoperative statin therapy (n=663; 31.3%) and those who did not (n=1,457; 68.7%). Propensity score matching resulted in 381 matched pairs, thus addressing baseline risk imbalances. Thirty-day mortality, readmission rates, postoperative complications, and length of stay were analyzed. Late survival was ascertained by the Social Security Death Index. RESULTS In the matched group, 30-day mortality was 1.3% (5 of 381) for statin-treated patients versus 4.2% (16 of 381) for statin-untreated patients (p=0.03). After a mean follow-up of 33±23 months, statin therapy was associated with significantly reduced mortality (hazard ratio 0.63, 95% confidence interval: 0.43 to 0.93, p=0.019), independent of known cardiac risk factors. Weighted log rank tests revealed that the mortality difference between the two cohorts occurred early after surgery (p=0.015). Statin users were less likely to be readmitted to the intensive care unit (3.4% versus 8.1%, p=0.01). There were no other significant differences between the two groups in terms of postoperative complications and length of stay. CONCLUSIONS Preoperative statin administration is associated with early reductions in mortality among patients undergoing isolated valvular heart surgery, leading to improved late survival. Future prospective analyses are warranted to optimize statin therapy in this patient population.

Impact of Aneurysm Repair on Thoracic Aorta Hemodynamics

We present pre- and postoperative imaging findings in a 29-year-old man with a bicuspid aortic valve (BAV) with fusion of the right and left coronary leaflets and a 6.1 cm × 6.3 cm ascending aorta aneurysm (Figure 1). The patient underwent a valve-sparing aortic root replacement with a 34-mm Dacron graft and BAV repair with resection of the raphe of the fused leaflet and leaflet shortening of the noncoronary cusp. Figure 1. Sagital ( A ) and axial ( B ) preoperative MRI demonstrating a 6.1×6.3 cm ascending aorta (AAo) aneurysm. To better understand the preoperative flow characteristics in the large aneurysm and the impact of surgical repair and reconstruction on thoracic aorta hemodynamics, time-resolved 3-dimensional phase contrast (4D flow) MRI was performed before and after surgery. The MRI examinations (pre: 3.0 T Skyra, post: 1.5 T Avanto, Siemens, Germany) included both 4D flow MRI (velocity sensitivity pre:150 cm/s, post: 250 cm/s, spatial/temporal resolution pre: 3.14×2.13×3.2 mm3/39 ms, post: 2.88×2.13×2.15 mm3/38ms) and dynamic 2-D cine imaging of the heart (steady-state free precession, spatial/temporal resolution pre: 1.25×1.25×6 mm3/29 ms post:1.8×1.8×6 mm3/39 ms). The study was approved by the local institutional review board, and informed consent was obtained from the patient. Blood flow patterns within the thoracic aorta were visualized using time-resolved 3D pathlines to illustrate complex blood flow dynamics over the entire cardiac cycle (EnSight, CEI). In addition, 3D velocity streamlines drawn tangent to the time-resolved velocity field were used to illustrate instantaneous flow dynamics in the thoracic aorta. Forward and …

A helping hand for regadenoson tests.

Noninvasive stress testing is ideally performed by allowing patients to exercise to maximal capacity. However, not all patients are able to perform sufficient exercise or are on medications that blunt the necessary heart rate increase. For these individuals, pharmacologic stress testing is performed, often with adjunctive treadmill exercise. Low-level exercise has been combined with pharmacologic stress for years, and has been shown to reduce side effects and improve image quality. Pharmacologic stress has also been combined with symptom-limited exercise in suitable patients as a means to obtain valuable functional data while ensuring adequate stress. Since its approval in 2008, regadenoson has become the most commonly used vasodilator used in pharmacologic perfusion imaging surpassing adenosine and dipyridamole. Although it involves an off-label use of the agent, interest and experience in protocols combining symptom-limited exercise and pharmacologic stress is increasing. That regadenoson can be administered as a bolus injection has invited the study of such protocols with this agent. Studies to date have shown that combining regadenoson with some form of exercise is feasible and safe. However, some patients we intend to stress with regadenoson cannot walk on a treadmill. What can we do for these patients to enhance their experience and improve image quality? In this issue of the journal, Janvier et al prospectively evaluate the safety, feasibility, and hemodynamic and imaging impact of a less commonly utilized exercise modality—handgrip—in combination with regadenoson administration. In this study, patients being evaluated for stable coronary artery disease were prospectively assigned to either a standard regadenoson (Reg) protocol or to a combined handgrip-regadenoson (HG-Reg) protocol. For the HG-Reg group, isometric handgrip exercise was started 2 minutes prior to regadenoson administration and continued for 5-7 minutes after the infusion. Feasibility of this protocol was measured by certain hemodynamic measurements such as heart rate and blood pressures variability between the study groups. Maximum heart rates were greater in the exercise group (HG-reg), but mean systolic blood pressures were similar between the two groups. Blood pressure fluctuations, particularly significant decreases in systolic blood pressure, were less likely in the HG-Reg group. Fewer patients in the HG-Reg group had any side effects of the test; however, typical vasodilator side effects such as chest discomfort were similar in both groups. Consistent with previous studies of utilizing exercise with pharmacologic stress protocols, myocardial image quality was at least comparable, if not better, in the HG-Reg group. Another benefit touted by the authors is that, because handgrip exercise resulted in a limited heart rate response, the potential risk of the ‘‘double stress’’ is significantly reduced, adding to the safety of this protocol. Issues to keep in mind regarding this study include the small cohort sizes and the lack of comparison of ischemia detection. Then again, this was just a preliminary study primarily focusing on safety and feasibility. A nice next step from this group would be the determination of the diagnostic ability of this protocol using a comparison of ischemic burden based on imaging results. In addition, a specific device was utilized for the handgrip exercise (CanDo Digi-Flex Hand Exerciser, not mentioned in the paper). It is not clear to us how this was used. Was the handgrip continuous or repeated? Was one hand used or two? Another question, but one this study was not designed to answer, is if the device is Reprint requests: Thomas A. Holly, Division of Cardiology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago IL; tholly@nm.org J Nucl Cardiol 2017;24:41–2. 1071-3581/

Leveraging electronic health record documentation for Failure Mode and Effects Analysis team identification

34.00 Copyright 2015 American Society of Nuclear Cardiology.

Impact of Beta-blocker, ACE Inhibitor, and ARB therapy on thoracic aorta wall shear stress in bicuspid aortic valve patients

Objective: Using Failure Mode and Effects Analysis (FMEA) as an example quality improvement approach, our objective was to evaluate whether secondary use of orders, forms, and notes recorded by the electronic health record (EHR) during daily practice can enhance the accuracy of process maps used to guide improvement. We examined discrepancies between expected and observed activities and individuals involved in a high-risk process and devised diagnostic measures for understanding discrepancies that may be used to inform quality improvement planning. Methods: Inpatient cardiology unit staff developed a process map of discharge from the unit. We matched activities and providers identified on the process map to EHR data. Using four diagnostic measures, we analyzed discrepancies between expectation and observation. Results: EHR data showed that 35% of activities were completed by unexpected providers, including providers from 12 categories not identified as part of the discharge workflow. The EHR also revealed sub-components of process activities not identified on the process map. Additional information from the EHR was used to revise the process map and show differences between expectation and observation. Conclusion: Findings suggest EHR data may reveal gaps in process maps used for quality improvement and identify characteristics about workflow activities that can identify perspectives for inclusion in an FMEA. Organizations with access to EHR data may be able to leverage clinical documentation to enhance process maps used for quality improvement. While focused on FMEA protocols, findings from this study may be applicable to other quality activities that require process maps.

Response to Letter Regarding Article, “Bicuspid Aortic Cusp Fusion Morphology Alters Aortic Three-Dimensional Outflow Patterns, Wall Shear Stress, and Expression of Aortopathy”

Background Bicuspid aortic valves (BAV) are associated with higher incidence of aortopathy such as aortic dilatation, dissection, and aortic valve stenosis. Recent 4D flow MRI studies have provided evidence that BAV aortopathy is associated with specific hemodynamic abnormalities and increased wall shear stress (WSS) which is thought to alter aortic endothelial cell function and induce remodeling and dilatation. Pharmacologic management of BAV is currently debated. It has been hypothesized that blood pressure control using medical therapy can decrease or reduce the rate of change to central arterial pressure and thus reduce wall forces such as wall shear stress (WSS) on the aneurysmal segment of the aorta to prevent aortic remodeling and dilatation. However, invivo studies investigating the effect of cardiac medications on aortic WSS in BAV patients are lacking. In this longitudinal follow-up 4D flow MRI study, the effects of Beta blockers (BB), Angiotensin converting enzyme inhibitors (ACEI), and Angiotensin II Receptor Blockers (ARB) on the aortic WSS was investigated using 4D Flow MRI.

Beta-blocker therapy does not reduce ascending aorta wall shear stress in patients with bicuspid aortic valve

We thank Hope and colleagues for their interesting and pertinent letter on our recent study in patients with bicuspid aortic valve (BAV), in which the relationship between bicuspid aortic valve morphology, the resulting flow patterns, and the aortopathy phenotype was examined.1 To confirm their initial comment, indeed, the ascending aortic flow displacement parameter was not normalized to the individual vessel diameter. We agree with Hope et al that flow displacement should ideally be normalized by the lumen diameter to account for interindividual differences in aortic geometry. Nonetheless, aortic diameters in the aorta size control group and the BAV patient groups in our study cohort were similar (4.1 versus 4.0 cm, respectively). Thus, the process of normalization did not affect the …

4D flow MRI demonstrates altered aortic hemodynamics in patients with right-left and right-noncoronary bicuspid aortic valve fusion patterns

Methods Right-left coronary leaflet fusion BAV patients on b-blockers (BB+) (n = 30, M:F = 23:7, age: 46 ± 14 years) and not on b-blockers (BB-) (n=30, M:F = 23:7, age: 46 ± 13 years) and healthy controls (n=15, age:43±11 years) underwent time-resolved, 3D phase contrast (4D flow) MRI. Patient groups were matched by systolic blood pressure (SBP), degree of aortic stenosis (AS), and AAo diameter (3.9 ± 0.7 vs. 3.9 ± 0.6 cm, p = 0.70). A 3D segmentation of the thoracic aorta was performed (MIMICS, Materlise, Belgium). Systolic 3D WSS was calculated in the thoracic aorta from 4D flow velocity acquisition and a sagittal maximum intensity projection (MIP) of WSS was generated.