The Clinical Impact of Imaging Surveillance and Clinic Visit Frequency after Acute Aortic Dissection.

BACKGROUND: Guidelines recommend frequent follow-up after acute aortic dissection (AAD), but optimal rates of follow-up are not clear. METHODS: We examined rates of imaging and clinic visits in 267 individuals surviving AAD during recommended intervals (≤1, > 1-3, > 3-6, > 6-12 months, then annually), frequency of adverse imaging findings, and the relationship between follow-up and mortality. RESULTS: Type A and B AAD were noted in 46 and 54% of patients, respectively. Mean follow-up was 54.7 ± 13.3 months, with 52 deaths. Adverse imaging findings peaked at 6 to 12 months (5.6%), but rarely resulted in an intervention (3.4% peak at 6-12 months). Compared with those with less frequent imaging, patients with imaging for 33 to 66% of intervals (p = 0.22) or ≥66% of intervals (p = 0.77) had similar adjusted survival. In comparison to patients with fewer clinic visits, those with visits in 33 to 66% of intervals experienced lower adjusted mortality (hazards ratio: 0.47, 95% confidence interval: 0.23-0.97, p = 0.04), with no difference seen in those with ≥66% (vs. < 33%) interval visits (p = 0.47). Imaging at 6 to 12 months (vs. none) was associated with decreased adjusted mortality (hazards ratio: 0.50, 95% confidence interval: 0.27-0.91, p = 0.02), while imaging during other intervals, or clinic visits during any specific intervals, was not associated with a difference in mortality (p > 0.05 for each). CONCLUSIONS: Adverse imaging findings following AAD are common, but rarely require prompt intervention. Patients with the lowest and highest rates of clinic visits experienced increased mortality. While the overall rate of surveillance imaging did not correlate with mortality, adverse imaging findings and related interventions peaked at 6 to 12 months after AAD, and imaging during this time was associated with improved survival.

Effect of Race on Echocardiographic Measures of Cardiac Structure and Function.

The relations between race and cardiac structure and function are incompletely understood. We hypothesized that race-specific differences in echocardiography measurements exist. We compared the relation between echocardiography measurements and race among 12,429 nonobese adults without known cardiovascular disease who underwent echocardiography. We compared measurements between whites (n = 10,508), blacks (n = 792), Asians (n = 628), Hispanics (n = 315), Native Americans (n = 34), and multiracial/other (n = 152) cohorts. Multivariate analysis compared measurements indexed to body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 46.9 ± 17.4 years and 60.5% were women. After multivariable adjustment and using whites as a baseline, there were significant differences (p <0.05) in left ventricular end-diastolic diameter/BSA for blacks (-0.5 mm/m2), Asians (0.4 mm/m2), Hispanics (0.2 mm/m2), and multiracial/others (0.1 mm/m2); septal wall thickness/BSA for blacks (0.4 mm/m2) and Asians (0.1 mm/m2); posterior wall thickness/BSA for blacks (0.4 mm/m2), Asians (0.1 mm/m2), Hispanics (0.04 mm/m2), and multiracial/others (0.03 mm/m2); left atrial diameter/BSA for Asians (0.2 mm/m2), Hispanics (0.3 mm/m2), and multiracial/others (0.1 mm/m2); septal and lateral e' for blacks (-0.7 cm/s; -0.9 cm/s); and peak tricuspid regurgitation gradient for blacks (4.3 mm Hg) and Asians (-0.9 mm Hg). Race is associated with significant differences in left ventricular size, left atrial size, mitral annular velocity, and tricuspid regurgitation gradient. Normal reference ranges for echocardiography measurements should utilize racially diverse cohorts to prevent misclassification of echocardiography findings based on race.

Differences in Echocardiographic Measures of Aortic Dimensions by Race.

It is not clear whether there are differences in aortic dimensions by race. Our hypothesis was that race-specific differences in aortic size exist. We compared the relation between race and aortic dimensions among 15,295 adults without known risk factors for cardiovascular disease or aortic dilatation, who underwent clinically indicated transthoracic echocardiography. We compared inner edge-to-inner edge measurements between whites (n = 12,932), blacks (n = 958), Asians (n = 827), Hispanics (n = 366), Native Americans (n = 38), and others (n = 174). Multivariate analysis compared measurements indexed with body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 49.9 ± 17.6 years, and 58.7% were female. On gender-specific comparisons, there were significant differences in aortic size between races (p <0.001 for each). Using whites as a baseline, multivariable analysis demonstrated that blacks had smaller BSA-indexed aortic sinus (-0.34 mm/m2, p <0.001) and ascending aorta (-0.43 mm/m2, p <0.001) dimensions; Asians had larger BSA-indexed aortic sinus (0.36 mm/m2, p <0.001), ascending aorta (0.41 mm/m2, p <0.001), and aortic arch (0.20 mm/m2, p = 0.002) dimensions; Hispanics had larger BSA-indexed aortic arch dimensions (0.15 mm/m2, p = 0.01); Native Americans had increased BSA-indexed aortic arch dimensions (0.32 mm/m2, p = 0.01); and other races had increased BSA-indexed aortic arch dimensions (0.11 mm/m2, p = 0.03). In a cohort without known risk factors for aortic dilatation, race is associated with significant differences in aortic dimensions. In conclusion, these findings suggest that reference ranges for aortic size should be established using racially diverse cohorts to prevent misdiagnosis of aortic dilatation based on race.

Indexing left ventricular wall thickness to body surface area improves prognostic value.

BACKGROUND: Guidelines provide normal ranges of left ventricular (LV) wall thicknesses (WT) without indexing. We hypothesized that indexing WT to body surface area (BSA) improves prognostic value. METHODS: We examined the relationship between WT and BSA in 9737 patients undergoing echocardiography without risk factors for LV hypertrophy other than obesity. We compared WT to BSA and examined the relationship of WT and LV mass index (LVMI) to mortality. RESULTS: There is a linear relationship between BSA and septal and posterior WT (r = 0.38, P < 0.001 for each). Higher quartiles of BSA were associated with increased WT (P < 0.001). After adjusting for age and gender, greater mean WT (MWT) (Hazards Ratio [HR] 1.10 per mm, 95% Confidence Interval [CI] 1.04-1.16, P = 0.001, C-statistic 0.66), LVMI (HR 1.01, 95% CI 1.001-1.01, P = 0.01, C-statistic 0.66), and indexed MWT (HR 1.34 per mm/m2 , 95% CI 1.23-1.47, P < 0.001, C-statistic 0.67) are each associated with increased mortality, with indexed MWT having the highest prognostic value. Each decile of indexed MWT ≥8th decile was associated with increased mortality compared to the 1st decile (P < 0.01 for each). Individuals with indexed MWT ≥8th decile (≥5.0 mm/m2 ) had increased adjusted mortality (HR 1.67, 95% CI 1.43-1.94, P < 0.001, C-statistic 0.67); this had improved prognostic value over guideline definitions of increased MWT (C-statistic 0.66) or LVMI (P = NS). CONCLUSIONS: We observe a linear relationship between BSA and WT. Indexing WT improves mortality prediction over LVMI and nonindexed WT. These findings support indexing WT to BSA.

Extracorporeal Membrane Oxygenation in a 29-Year-Old Man with Pneumocystis jirovecii Respiratory Failure and AIDS.

The use of extracorporeal membrane oxygenation (ECMO) in patients who have acute respiratory distress syndrome has been generally beneficial. However, because of various concerns, ECMO has rarely been used in patients who have human immunodeficiency virus infection with or without acquired immune deficiency syndrome. We report our successful use of venovenous ECMO in a 29-year-old man who presented with severe respiratory distress secondary to Pneumocystis jirovecii pneumonia associated with undiagnosed infection with the human immunodeficiency virus and acquired immune deficiency syndrome. After highly active antiretroviral therapy was begun, acute immune reconstitution inflammatory syndrome developed. The patient's respiratory condition deteriorated rapidly; he was placed on venovenous ECMO for 19 days and remained intubated thereafter. After a 65-day hospital stay and inpatient pulmonary rehabilitation, he recovered fully. In addition to presenting this case, we review the few previous reports and note the multidisciplinary medical and surgical support necessary to treat similar patients.

Presenting Systolic Blood Pressure and Outcomes in Patients With Acute Aortic Dissection.

BACKGROUND: Presenting systolic blood pressure (SBP) is a powerful predictor of mortality in many cardiovascular settings, including acute coronary syndromes, cardiogenic shock, and acute heart failure. OBJECTIVES: This study evaluated the association of presenting SBP with in-hospital outcomes, specifically all-cause mortality, in acute aortic dissection (AAD). METHODS: The study included 6,238 consecutive patients (4,167 with type A and 2,071 with type B AAD) enrolled in the International Registry of Acute Aortic Dissection. Patients were stratified in 4 groups according to presenting SBP: SBP >150, SBP 101 to 150, SBP 81 to 100, or SBP ≤80 mm Hg. RESULTS: The relationship between presenting SBP and in-hospital mortality displayed a J-curve association, with significantly higher mortality rates in patients with very high SBP (26.3% for SBP >180 mm Hg in type A AAD, 13.3% for SBP >200 mm Hg in type B AAD; p = 0.005 and p = 0.018, respectively) as well as in those with SBP ≤100 mm Hg (29.9% in type A, 22.4% in type B; p = 0.033 and p = 0.015, respectively). This relationship was mainly from increased rates of in-hospital complications (acute renal failure, coma, and mesenteric ischemia/infarction in patients with SBP >150 mm Hg; stroke, coma, cardiac tamponade, myocardial ischemia/infarction, and acute renal failure in patients with SBP ≤80 mm Hg). Notably, presenting SBP ≤80 mm Hg was independently associated with in-hospital mortality in both type A (p = 0.001) and type B AAD (p = 0.003). CONCLUSIONS: Presenting SBP showed a clear J-curve relationship with in-hospital mortality in patients with AAD. Although this association was related to increased rates of comorbid conditions at the edges of the curve, SBP ≤80 mm Hg was an independent correlate of in-hospital mortality.

Acute aortic syndromes: diagnosis and management, an update.

Acute aortic syndromes (AAS) encompass a constellation of life-threatening medical conditions including classic acute aortic dissection (AAD), intramural haematoma, and penetrating atherosclerotic aortic ulcer. Given the non-specific symptoms and physical signs, a high clinical index of suspicion is necessary to detect the disease before irreversible lethal complications occur. In order to reduce the diagnostic time delay, a comprehensive flowchart for decision-making based on pre-test sensitivity of AAS has been designed by the European Society of Cardiology guidelines on aortic diseases and should be thus applied in the emergency scenario. When the definitive diagnosis is made, prompt and appropriate therapeutic interventions should be undertaken if indicated by a highly specialized aortic team. Urgent surgery for AAD involving the ascending aorta (Type A) and medical therapy alone for AAD not involving the ascending aorta (Type B) are typically recommended. In complicated Type B AAD, thoracic endovascular aortic repair (TEVAR) is generally indicated. On the other hand, in uncomplicated Type B AAD, pre-emptive TEVAR rather than medical therapy alone to prevent late complications, while intuitive, requires further study in randomized cohorts. Finally, it should be highlighted that there is an urgent need to increase awareness of AAS worldwide, including dedicated education/prevention programmes, and to improve diagnostic and therapeutic strategies, outcomes, and lifelong surveillance.

SYNTAX Score Derived From Coronary CT Angiography for Prediction of Complex Percutaneous Coronary Interventions.

RATIONALE AND OBJECTIVES: SYNTAX score is a useful metric determined at the time of invasive coronary angiography (ICA) to assess the complexity of coronary artery disease, and improves prediction of complications at the time of percutaneous complex intervention (PCI). We aimed to determine whether SYNTAX score can be reliably determined from coronary computed tomography angiography (CCTA) and whether a CCTA-derived SYNTAX score can predict complex PCI. MATERIALS AND METHODS: SYNTAX scores were calculated on per-patient, per-vessel, and per-segment basis in 154 consecutive patients who underwent CCTA and ICA. PCI complexity in 113 patients who underwent intervention was defined by total fluoroscopy time and contrast volume. RESULTS: Compared to ICA, CCTA detected 285 of 302 (94%) obstructive lesions in 230 vessels, for which PCI was performed for 154 lesions in 131 vessels. Overall, on a per-patient basis, ICA-derived SYNTAX score was lower in comparison to CCTA-derived score (10.2 ± 8.0 vs 10.9 ± 8.3, P = 0.001). As compared to lesions in the lowest CCTA-derived segmental SYNTAX tertile, lesions in the highest tertile required longer fluoroscopy time (17.5 ± 12 min vs 11.5 ± 7.9 min, P = 0.01) and greater contrast volume (215.4 ± 125.5 mL vs 144.3 ± 49 mL, P = 0.02). CONCLUSION: SYNTAX scores derived from CCTA are concordant with those derived from ICA and correspond with complex PCI.

Iterative Reconstruction Results in Larger Computed Tomography Measurements of Iliofemoral Artery Diameter in Patients Referred for Transcatheter Aortic Valve Replacement.

OBJECTIVES: We hypothesized that improved iterative reconstruction increases image quality and reduces artifacts for iliofemoral artery computed tomography imaging in patients referred for transcatheter aortic valve replacement (TAVR). METHODS: We examined 56 consecutive patients undergoing computed tomography for possible TAVR and compared image quality and iliofemoral artery size between adaptive statistical iterative reconstructions (ASIRs) and improved model-based iterative reconstructions (MBIRs). RESULTS: Model-based iterative reconstruction (vs ASIR) was associated with improved (P < 0.001 for each) image quality (3.4 ± 0.8 vs 2.8 ± 1.0), beam hardening (3.5 ± 0.8 vs 3.0 ± 1.1), and wall definition (3.6 ± 0.6 vs 3.1 ± 0.8). Image signal-to-noise ratios (20.4 ± 10.1 vs 13.7 ± 6.6, P < 0.001) were also increased with MBIR as compared with ASIR. Mean iliofemoral artery size was larger using MBIR compared with ASIR (left, 7.7 ± 1.5 vs 7.4 ± 1.7 mm, P < 0.001; right, 7.8 ± 1.2 vs 7.4 ± 1.5 mm, P = 0.008). CONCLUSIONS: In patients referred for TAVR, improved MBIR resulted in higher image quality, reduced artifacts, and larger iliofemoral artery diameters compared with standard iterative reconstructions.

Mortality Predictors in Patients Referred for but Not Undergoing Transcatheter Aortic Valve Replacement.

Although transcatheter aortic valve replacement (TAVR) has expanded the proportion of patients with aortic stenosis (AS) who are candidates for valve replacement, some patients remain untreated, and their outcomes are not clear. We evaluated 172 consecutive patients with severe symptomatic AS referred for TAVR who declined (n = 55) or were not candidates for (n = 117) intervention. We examined clinical and echocardiographic variables associated with mortality. There were 77 deaths, and mean follow-up was 17.9 ± 10.9 months for survivors. Mortality rate at 1 and 2 years was 39.2% and 52.6%, respectively. There was a significant difference in mortality rate between patients who declined the procedure and those who were not candidates (p = 0.001), with 1-year mortality rates of 20.6% and 48.4%, respectively. On multivariate analysis, 4 variables were independently associated with all-cause mortality: New York Heart Association Class IV heart failure (hazard ratio [HR] 2.6, 95% confidence interval [CI] 1.6 to 4.2, p <0.001), glomerular filtration rate <48 ml/min (HR 2.1, 95% CI 1.3 to 3.4, p = 0.002), albumin <3.9 g/dl (HR 1.9, 95% CI 1.2 to 3.1, p = 0.007), and ejection fraction <50% (HR 1.9, 95% CI 1.4 to 3.0, p = 0.01). In this new era with expanded treatment options, patients with severe symptomatic AS who remain untreated after referral for TAVR experience a mortality rate of 39% at 1 year. The presence of advanced heart failure, renal dysfunction, low albumin, and/or left ventricular dysfunction identifies patients at higher risk of mortality.

Effectiveness of a low contrast load CT angiography protocol in octogenarians and nonagenarians being evaluated for transcatheter aortic valve replacement.

INTRODUCTION: Transcatheter aortic valve replacement (TAVR) typically requires computed tomographic angiography (CTA) for aortoiliofemoral assessment to determine feasibility of a transfemoral approach, although many candidates being considered for TAVR are at increased risk of contrast-induced nephropathy (CIN). OBJECTIVE: To determine the feasibility and safety of a load contrast load CTA protocol in octogenarians and nonagenarians at risk of CIN. APPROACH: We evaluated 54 consecutive octogenarians and nonagenarians considered for TAVR who underwent CTA using a standard contrast protocol (n=21) versus a protocol incorporating low-dose contrast in patients at risk of CIN (n=33). We compared clinical characteristics, CTA image quality (score 1-4) and interpretability, and clinical outcomes, including CIN and vascular complications. RESULTS: The mean age was 88.5±4.0 years, 37% were male, and chronic renal insufficiency was common in both the standard and low-dose contrast cohorts (57% vs. 70%, P=.39). The low-dose contrast protocol was associated with a significantly less contrast volume compared to standard contrast protocol (127±18 ml vs 76±55 ml, P<.001). Individuals imaged using low-dose (n=16) versus standard (n=17) contrast protocols received 80% less contrast volume (23±10 vs. 125±23 ml, P<.001). There was similar graded image quality (3.8±0.4 vs. 3.9±0.3, P=.76) and interpretability (100% for each, P=1.0) between standard and low-dose contrast protocol groups. There was no significant difference in rates of CIN after CTA between standard and low-dose contrast protocol groups (10% vs. 3%, P=.55), with no CIN events in those imaged by low-dose CTA. There were no major vascular injuries associated with TAVR or pigtail insertion, no major bleeding for CTA, and no noninterpretable studies in all patients. CONCLUSION: In this proof-of-principle study, a low-dose contrast protocol appears feasible and safe in octogenarians and nonagenarians undergoing screening for TAVR, and results in significant reduction in contrast load as compared to a standard contrast protocol without observed differences in image quality or safety.