Gaby Weissman

Complications and Outcome of Balloon Aortic Valvuloplasty in High-Risk or Inoperable Patients

OBJECTIVES This study aimed to determine the success, complications, and survival of patients after balloon aortic valvuloplasty (BAV). BACKGROUND The introduction of transcatheter aortic valve implantation (TAVI) BAV has led to a revival in the treatment of patients with severe aortic stenosis. METHODS A cohort of 262 patients with severe aortic stenosis underwent 301 BAV procedures. Of these, 39 (14.8%) patients had ≥2 BAV procedures. Clinical, hemodynamic, and follow-up mortality data were collected. RESULTS The cohort mean age was 81.7 ± 9.8 years, and the mean Society of Thoracic Surgeons and logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) was 13.3 ± 6.7 and 45.6 ± 21.6, respectively. BAV was performed as a bridge to TAVI or to surgical aortic valve replacement in 28 patients (10.6%) and for symptom relief in 234 (89.4%). The mean aortic valve area (AVA) increased from 0.58 ± 0.3 cm(2) to 0.96 ± 0.3 cm(2) (p < 0.001). Of these, 111 (45.0%) had final AVA >1 cm(2), and in 195 patients (79%), AVA increased by >40%. De novo BAV resulted in a higher mean increase in AVA 0.41 ± 0.24 cm(2) versus 0.28 ± 0.24 cm(2) in redo BAV (p = 0.003). Serious adverse events occurred in 47 patients (15.6%), intraprocedural death in 5 (1.6%), stroke in 6 (1.99%), coronary occlusion in 2 (0.66%), severe aortic regurgitation in 4 (1.3%), resuscitation/cardioversion in 5 (1.6%), tamponade in 1 (0.33%), and permanent pacemaker in 3 (0.99%). A vascular complication occurred in 21 patients (6.9%); 34 (11.3%) had a post-procedure rise in creatinine >50%; and 3 (0.99%) required hemodialysis. During median follow-up of 181 days, the mortality rate was 50% (n = 131). The mortality rate in the group with final AVA >1 cm(2) was significantly lower than in the group with final AVA of <1 cm(2) (36.4% vs. 57.9%, p < 0.001). Final AVA was associated with lower mortality (hazard ratio: 0.46, p = 0.03). BAV as a bridge to TAVI or surgical aortic valve replacement had a better outcome compared with BAV alone: mortality rate 7 (25%) versus 124 (52.9%), respectively (p < 0.0001). CONCLUSIONS Long-term survival is poor after BAV alone. BAV as a bridge to percutaneous or surgical aortic valve replacement is feasible, safe, and associated with better outcome than BAV alone.

Correlates and Causes of Death in Patients With Severe Symptomatic Aortic Stenosis Who Are Not Eligible to Participate in a Clinical Trial of Transcatheter Aortic Valve Implantation

Background— Transcatheter aortic valve implantation is currently being evaluated in patients with severe aortic stenosis who are considered high-risk surgical candidates. This study aimed to detect incidences, causes, and correlates of mortality in patients ineligible to participate in transcatheter aortic valve implantation studies. Methods and Results— From April 2007 to July 2009, a cohort of 362 patients with severe aortic stenosis were screened and did not meet the inclusion/exclusion criteria necessary to participate in a transcatheter aortic valve implantation trial. These patients were classified into 2 groups: group 1 (medical): 274 (75.7%): 97 (35.4%) treated medically and 177 (64.6%) treated with balloon aortic valvuloplasty; and group 2 (surgical): 88 (24.3%). The medical/balloon aortic valvuloplasty group had significantly higher clinical risk compared with the surgical group, with significantly higher Society of Thoracic Surgeons score (12.8±7.0 versus 8.5±5.1; P<0.001) and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) (42.4±22.8 versus 24.4±18.1; P<0.001). The medical/balloon aortic valvuloplasty group had a higher New York Heart Association functional class, incidence of renal failure, and lower ejection fraction. During median follow-up of 377.5 days, mortality in the medical/balloon aortic valvuloplasty group was 102 (37.2%), and during median follow-up of 386 days, mortality in the surgical group was 19 (21.5%). Multivariable adjustment analysis identified renal failure (hazard ratio [HR]: 5.60), New York Heart Association class IV (HR: 5.88), and aortic systolic pressure (HR: 0.99) as independent correlates for mortality in the medical group, whereas renal failure (HR: 7.45), Society of Thoracic Surgeons score (STS; HR: 1.09) and logistic EuroSCORE (HR: 1.45) were correlates of mortality in the in the surgical group. Conclusion— Patients with severe symptomatic aortic stenosis not included in transcatheter aortic valve implantation trials do poorly and have extremely high mortality rates, especially in nonsurgical groups, and loss of quality of life in surgical groups.

Effect of hybrid iterative reconstruction technique on quantitative and qualitative image analysis at 256-slice prospective gating cardiac CT

AbstractObjectivesTo evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at 256-slice cardiac CT.MethodsProspective cardiac CT images from 20 patients were analysed. Paired image sets were created using 3 reconstructions, i.e. filtered back projection (FBP) and moderate- and high-level iterative reconstructions. Quantitative parameters including CT-attenuation, noise, and contrast-to-noise ratio (CNR) were determined in both proximal- and distal coronary segments. Image quality was graded on a 4-point scale.ResultsCoronary CT attenuation values were similar for FBP, moderate- and high-level iterative reconstruction at 293 ± 74-, 290 ± 75-, and 283 ± 78 Hounsfield units (HU), respectively. CNR was significantly higher with moderate- and high-level iterative reconstructions (10.9 ± 3.5 and 18.4 ± 6.2, respectively) than FBP (8.2 ± 2.5) as was the visual grading of proximal vessels. Visualisation of distal vessels was better with high-level iterative reconstruction than FBP. The mean number of assessable segments among 289 segments was 245, 260, and 267 for FBP, moderate- and high-level iterative reconstruction, respectively; the difference between FBP and high-level iterative reconstruction was significant. Interobserver agreement was significantly higher for moderate- and high-level iterative reconstruction than FBP.ConclusionsCardiac CT using hybrid iterative reconstruction yields higher CNR and better image quality than FBP.Key Points• Cardiac CT helps clinicians to assess patients with coronary artery disease • Hybrid iterative reconstruction provides improved cardiac CT image quality • Hybrid iterative reconstruction improves the number of assessable coronary segments • Hybrid iterative reconstruction improves interobserver agreement on cardiac CT

Ultra-low-dose intra-arterial contrast injection for iliofemoral computed tomographic angiography.

OBJECTIVES This study sought to evaluate the feasibility of using ultra-low-dose intra-arterial contrast injection for iliofemoral computed tomographic (CT) angiography to follow diagnostic cardiac catheterization. BACKGROUND Cardiovascular interventions such as percutaneous aortic valve replacement require transfemoral delivery of large-bore intra-arterial catheters; therefore, pre-procedural assessment of aortoiliofemoral anatomy is important. CT angiography is ideal for this purpose but requires a large volume of intravenous contrast. METHODS Consecutive patients requiring evaluation of aortoiliofemoral anatomy underwent conventional anteroposterior projection iliac angiography during cardiac catheterization. A pigtail catheter was left in situ in the infrarenal abdominal aorta, and patients were transferred to the CT suite. Subsequently, 10 to 15 ml of contrast diluted with normal saline was injected intra-arterially via the pigtail catheter while a spiral CT of the abdomen and pelvis was acquired. Conventional angiographic and CT images were analyzed independently to assess suitability for large-bore (7-mm-diameter)intra-arterial catheter access. RESULTS Excellent CT image quality was achieved in 34 of 37 patients (92%). The mean contrast dose for CT was 12 +/- 2 ml. In 9 patients (24%), CT changed the assessment of femoral access feasibility. Furthermore, in another 7 patients (19%), unfavorable anatomy as shown by CT directed the avoidance of a particular side. Overall, CT findings altered the interventional approach in 16 patients (43%). There was no significant deterioration detected in renal function after coronary and CT angiography (estimated glomerular filtration rate 54.8 +/- 3.8 ml/min before 53.3 +/- 3.9 ml/min after, p = 0.55). CONCLUSIONS High-quality aortoiliofemoral CT angiography can be obtained with a technical success rate of >90% using 10 to 15 ml of contrast injected via a catheter in the abdominal aorta, and offers an alternative to conventional X-ray or CT angiography with high-volume intravenous contrast injection.

Iterative model reconstruction: improved image quality of low-tube-voltage prospective ECG-gated coronary CT angiography images at 256-slice CT.

OBJECTIVES To investigate the effects of a new model-based type of iterative reconstruction (M-IR) technique, the iterative model reconstruction, on image quality of prospectively gated coronary CT angiography (CTA) acquired at low-tube-voltage. METHODS Thirty patients (16 men, 14 women; mean age 52.2 ± 13.2 years) underwent coronary CTA at 100-kVp on a 256-slice CT. Paired image sets were created using 3 types of reconstruction, i.e. filtered back projection (FBP), a hybrid type of iterative reconstruction (H-IR), and M-IR. Quantitative parameters including CT-attenuation, image noise, and contrast-to-noise ratio (CNR) were measured. The visual image quality, i.e. graininess, beam-hardening, vessel sharpness, and overall image quality, was scored on a 5-point scale. Lastly, coronary artery segments were evaluated using a 4-point scale to investigate the assessability of each segment. RESULTS There was no significant difference in coronary arterial CT attenuation among the 3 reconstruction methods. The mean image noise of FBP, H-IR, and M-IR images was 29.3 ± 9.6, 19.3 ± 6.9, and 12.9 ± 3.3 HU, respectively, there were significant differences for all comparison combinations among the 3 methods (p<0.01). The CNR of M-IR was significantly better than of FBP and H-IR images (13.5 ± 5.0 [FBP], 20.9 ± 8.9 [H-IR] and 39.3 ± 13.9 [M-IR]; p<0.01). The visual scores were significantly higher for M-IR than the other images (p<0.01), and 95.3% of the coronary segments imaged with M-IR were of assessable quality compared with 76.7% of FBP- and 86.9% of H-IR images. CONCLUSIONS M-IR can provide significantly improved qualitative and quantitative image quality in prospectively gated coronary CTA using a low-tube-voltage.

Accuracy of Computed Tomographic Angiography for Stenosis Quantification Using Quantitative Coronary Angiography or Intravascular Ultrasound as the Gold Standard

Computed tomographic angiography (CTA) is considered to have limited accuracy for quantifying exact percent diameter stenosis in coronary arteries. However, most studies evaluating CTA use quantitative coronary angiography (QCA) as the gold standard, a technique with its own limitations. We sought to determine whether CTA measurements of stenosis severity correlate better with intravascular ultrasound (IVUS) than with QCA. Luminal dimensions of 67 de novo coronary lesions were measured by CTA, IVUS, and QCA. IVUS was performed when lesion severity by angiography was equivocal. Mean percent diameter stenosis by QCA was 51 +/- 9.8% and mean IVUS minimal luminal area was 3.8 +/- 1.8 mm(2). There was a moderate correlation between CTA minimal luminal area and IVUS minimal luminal area (r(2) = 0.41, p <0.001), but no relation between CTA and QCA measurements of minimal luminal diameter (r(2) = 0.01, p = 0.57) or diameter stenosis (r(2) = 0.02, p = 0.31). There was also no relation between IVUS minimal luminal area and QCA diameter stenosis (r(2) = 0.01, p = 0.50). When lesions with moderate or severe calcification were excluded, the correlation between CTA minimal luminal area and IVUS minimal luminal area was good (r(2) = 0.68, p <0.001). In conclusion, in this cohort of patients with intermediate-grade lesions on cardiac catheterization, absolute measurements of stenosis severity on CTA correlated with IVUS but not with QCA. Our findings suggest that limitations of quantitative coronary angiography as a gold standard need to be considered in studies evaluating the accuracy of coronary CTA.

Viability imaging by cardiac computed tomography

First-pass perfusion and delayed enhancement cardiac imaging have been shown to be feasible by cardiac CT. However, questions remain about its reliability, and ideal scanning parameters have yet to be fully established. In general, scar imaging with cardiac CT typically requires 2 scans, with first-pass perfusion information derived from the same data set used to visualize the coronary arteries. Reduced contrast enhancement on first-pass cardiac CT images represents reduced perfusion. Higher doses of contrast are required to perform viability imaging by cardiac CT. Approximately 10 minutes after contrast administration, viability information is obtained by performing a second (noncontrast) scan. In addition to the concepts of perfusion and viability imaging by cardiac CT, we review parameters such as scan timing, tube settings, contrast delivery, reconstruction, and postprocessing techniques, as well as the associated pitfalls and technical limitations in perfusion and viability imaging by cardiac CT.

The Need for Standardized Methods for Measuring the Aorta Multimodality Core Lab Experience from the GenTAC Registry

OBJECTIVES This study sought to evaluate variability in aortic measurements with multiple imaging modalities in clinical centers by comparing with a standardized measuring protocol implemented in a core laboratory. BACKGROUND In patients with aortic disease, imaging of thoracic aorta plays a major role in risk stratifying individuals for life-threatening complications and in determining timing of surgical intervention. However, standardization of the procedures for performance of aortic measurements is lacking. METHODS To characterize the diversity of methods used in clinical practice, we compared aortic measurements performed by echocardiography, computed tomography (CT), and magnetic resonance imaging (MRI) at the 6 GenTAC (National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) clinical centers to those performed at the imaging core laboratory in 965 studies. Each center acquired and analyzed their images according to local protocols. The same images were subsequently analyzed blindly by the core laboratory, on the basis of a standardized protocol for all imaging modalities. Paired measurements from clinical centers and core laboratory were compared by mean of differences and intraclass correlation coefficient (ICC). RESULTS For all segments of the ascending aorta, echocardiography showed a higher ICC (0.84 to 0.93) than CT (0.84) and MRI (0.82 to 0.90), with smaller mean of differences. MRI showed higher ICC for the arch and descending aorta (0.91 and 0.93). In a mixed adjusted model, the different imaging modalities and clinical centers were identified as sources of variability between clinical and core laboratory measurements, whereas age groups or diagnosis at enrollment were not. CONCLUSIONS By comparing core laboratory with measurements from clinical centers, our study identified important sources of variability in aortic measurements. Furthermore, our findings with regard to CT and MRI suggest a need for imaging societies to work toward the development of unifying acquisition protocols and common measuring methods.

Impact of triggering event in outcomes of stress-induced (Takotsubo) cardiomyopathy

Background: Takotsubo syndrome is also known as stress cardiomyopathy because of the regularity with which it has been associated with physical or emotional stress. Such stress may well be a “trigger” of the syndrome. Aims: This analysis was undertaken to describe our experience with this disorder and in particular to examine the effects of the underlying trigger on outcomes. Methods: We conducted a retrospective review of the medical records of 345 consecutive patients treated at our institution from 2006 to 2014. All presented with acute cardiac symptoms, a characteristic left ventricular contraction pattern (typical, atypical), and no major obstructive coronary artery disease. Patients were grouped based on their triggering event: (a) medical illness; (b) post-operative period; (c) emotional distress; or (d) no identified trigger. Baseline demographic characteristics, death in hospital, length of stay in hospital, and cardiac complications were abstracted from the patients’ medical records. Results: The mean±SD age of the population was 72±12 years and 91% were women. No significant difference in baseline characteristics was noted between the groups except for a higher prevalence of African Americans in the group with a medical illness. ST elevation was noted in 13.3% of patients and the average peak troponin level was 5±12 ng/dl. An inotropic drug was required in 49 (14.2%) patients, an intra-aortic balloon pump in 37 (10.7%) patients, and mechanical ventilation in 54 (15.7%) patients; 43.5% required treatment in the intensive care unit. Overall, 12 (3.5%) patients died. In only two (16.7%) patients was a there a direct cardiac cause of death. In those patients in whom the cardiac manifestations seemed to be triggered by a medical illness, the death rate was 7.1% and this was significantly higher than in the other groups (p=0.03). Medical illness (odds ratio=6.25, p=0.02) and ST elevation (odds ratio=5.71, p=0.04) were both significantly associated with death. Conclusions: Our study showed that different triggers for Takotsubo syndrome confer different prognoses, with medical illness conferring the worst prognosis. Overall, the in-hospital death rate was low and mostly related to non-cardiac death secondary to the underlying medical illness. Although an unidentified trigger was prevalent in a third of this population, efforts should be made to identify the triggering event to classify the risk group of patients with Takotsubo syndrome.

Retroperitoneal hemorrhage after percutaneous coronary intervention in the current practice era: Clinical outcomes and prognostic value of abdominal/pelvic computed tomography†

Background: Retroperitoneal hemorrhage (RPH) is a serious but infrequent complication of percutaneous coronary intervention (PCI). This study aimed to describe the clinical outcomes of patients who developed RPH following PCI in the current practice era, with particular focus on treatment strategies and the related prognostic value of abdominal/pelvic computed tomography (CT). Methods: Among 20,904 patients undergoing PCI, we identified 93 RPH (0.45%) confirmed by CT or by unequivocal surgical findings. We identified three groups with RPH for comparison: patients who developed refractory shock (systolic blood pressure <80 mm Hg for ≥30 min despite fluids and vasopressors, n = 16 [17.2%]); patients with transient hypotension (<30 min, n = 34 [36.6%]); and patients without hypotension (n = 43 [46.2%]). The primary endpoint was a composite of in‐hospital mortality, myocardial infarction, and cerebral vascular accident (CVA). Results: Baseline clinical, angiographic, and procedural characteristics were similar among the three groups. Patients who developed refractory shock had significantly more bleeding quantified by abdominal/pelvic CT (P < 0.001), had a higher rate and amount of red blood cell transfusion (P < 0.001), and were managed invasively more frequently (68.7%) than the rest of the population. The primary endpoint trended higher in patients presenting with refractory shock; however, this difference was not statistically significant. The volume of bleeding quantified by CT and the timing of imaging diagnosis did not correlate with the primary endpoint. Red blood cell transfusion, but not clopidogrel discontinuation, was associated with the primary endpoint. Conclusions: RPH remains as a serious complication of PCI and is associated with high rates of mortality and morbidity independently of the therapeutic strategy. In patients who were hemodynamically stable, RPH volume as quantified by non‐contrast abdominal/pelvic CT did not contribute to prognosis.