Exercise-induced hypoxia among emergency department patients admitted for suspected COVID-19.

BACKGROUND: Exercise-induced hypoxia (EIH) has been assessed at ED triage as part of an assessment of COVID-19; however, evidence supporting this practice is incomplete. We assessed the use of a 1-minute sit-to-stand exercise test among ED patients admitted for suspected COVID-19. METHODS: A case note review of all ED patients assessed for suspected COVID-19 between March and May 2020 at Monklands University Hospital was conducted. Demographic characteristics, clinical parameters, baseline blood tests and radiographic findings, hospital length of stay, intensive care and maximum oxygen requirement were obtained for those admitted. Using logistic regression, the association between EIH at admission triage and COVID-19 diagnosis was explored adjusting for confounding clinical parameters. RESULTS: Of 127 ED patients admitted for possible COVID-19, 37 were ultimately diagnosed with COVID-19. 36.4% of patients with COVID-19 and EIH had a normal admission chest radiograph. In multivariate analysis, EIH was an independent predictor of COVID-19 (adjusted OR 3.73 (95% CI (1.25 to 11.15)), as were lymphocyte count, self-reported exertional dyspnoea, C-reactive peptide and radiographic changes. CONCLUSIONS: This observational study demonstrates an association between EIH and a COVID-19 diagnosis. Over one-third of patients with COVID-19 and EIH exhibited no radiographic changes. EIH may represent an additional tool to help predict a COVID-19 diagnosis at initial presentation and may assist in triaging need for admission.

Comparison of a low carbohydrate intake and standard carbohydrate intake on refeeding hypophosphatemia in children and adolescents with anorexia nervosa: a pilot randomised controlled trial.

BACKGROUND: Nutritional rehabilitation for patients with anorexia nervosa involves balancing the need for weight gain whilst mitigating the risk of refeeding syndrome. Graded caloric increases and restriction of calories from carbohydrate have been used to minimise the risk of developing refeeding hypophosphatemia. There is little evidence to support the recommended nutrient composition, specifically the recommended carbohydrate intake that is safe in this population. The aim of this pilot study was to compare the effect of a low and a standard carbohydrate feeding protocol on serum phosphate levels in children and adolescents with anorexia nervosa. METHODS: A pilot study of 23 children and adolescents with anorexia nervosa admitted for medical stabilisation to the adolescent ward of a tertiary hospital was undertaken. Participants were commenced on an oral feeding protocol and were randomly allocated to isocaloric meal plans that were either low carbohydrate (< 40% total energy from carbohydrate) or standard carbohydrate (50-60% total energy from carbohydrate). Serum phosphate levels were monitored daily across the first week and twice weekly thereafter. Clinical status, including weight gain, was monitored throughout admission. RESULTS: 52% (n = 12) of participants were allocated to the low carbohydrate group and 48% (n = 11) were allocated to the standard carbohydrate group. No patients in either of the diet groups developed refeeding hypophosphatemia in the first seven days of admission. Weight gain during the first week was significantly higher in the standard carbohydrate diet (1.4 kg/wk ± 0.5) compared to the low carbohydrate diet (0.6 kg/wk ± 0.9), p value 0.03. Participants from both diet groups were largely orally fed with less than 10% of the total number of meals and/or snacks across both groups provided as nutrition supplement drinks, either orally or enterally. CONCLUSION: This pilot study supports that a standard carbohydrate intake (providing 50-60% of total energy from carbohydrate) optimises nutritional rehabilitation without increasing the risk of refeeding hypophosphatemia in adolescent inpatients with anorexia nervosa. CTN: ACTRN12621000300875. Plain English Summary: People with eating disorders who are underweight or malnourished, such as patients with anorexia nervosa, are at risk of refeeding syndrome when they receive treatment and return to regular eating. Refeeding syndrome may cause fluid and electrolyte shifts. This can occur as a result of the reintroduction of carbohydrates, and can have potentially life-threatening consequences if not managed appropriately. Refeeding hypophosphatemia is one of the early markers of refeeding syndrome. This study compared patients who were provided a low carbohydrate diet (40% total energy from carbohydrate) to those who were provided a standard carbohydrate diet (50-60% total energy from carbohydrate) to see if patients from either group were more at risk of developing refeeding syndrome. No patients in either of the diet groups developed refeeding hypophosphatemia. This pilot study may help to ensure that when patients get treated for their eating disorder in hospital, they can return to a normal diet as soon as possible with close medical monitoring.

Effect of ACAT inhibition on the progression of coronary atherosclerosis.

BACKGROUND: The enzyme acyl-coenzyme A:cholesterol acyltransferase (ACAT) esterifies cholesterol in a variety of tissues. In some animal models, ACAT inhibitors have antiatherosclerotic effects. METHODS: We performed intravascular ultrasonography in 408 patients with angiographically documented coronary disease. All patients received usual care for secondary prevention, including statins, if indicated. Patients were randomly assigned to receive the ACAT inhibitor pactimibe (100 mg per day) or matching placebo. Ultrasonography was repeated after 18 months to measure the progression of atherosclerosis. RESULTS: The primary efficacy variable analyzing the progression of atherosclerosis--the change in percent atheroma volume--was similar in the pactimibe and placebo groups (0.69 percent and 0.59 percent, respectively; P=0.77). However, both secondary efficacy variables assessed by means of intravascular ultrasonography showed unfavorable effects of pactimibe treatment. As compared with baseline values, the normalized total atheroma volume showed significant regression in the placebo group (-5.6 mm3, P=0.001) but not in the pactimibe group (-1.3 mm3, P=0.39; P=0.03 for the comparison between groups). The atheroma volume in the most diseased 10-mm subsegment regressed by 3.2 mm3 in the placebo group, as compared with a decrease of 1.3 mm3 in the pactimibe group (P=0.01). The combined incidence of adverse cardiovascular outcomes was similar in the two groups (P=0.53). CONCLUSIONS: For patients with coronary disease, treatment with an ACAT inhibitor did not improve the primary efficacy variable (percent atheroma volume) and adversely affected two major secondary efficacy measures assessed by intravascular ultrasonography. ACAT inhibition is not an effective strategy for limiting atherosclerosis and may promote atherogenesis. (ClinicalTrials.gov number, NCT00268515.).

Application of intravascular ultrasound in anti-atherosclerotic drug development.

The background use of a number of established therapies presents a key challenge for the development of novel anti-atherosclerotic agents: how to predict potential efficacy before the completion of long-term trials with endpoints such as mortality. This challenge has stimulated the search to develop intermediate measures of efficacy. Recent advances now allow intravascular ultrasound (IVUS) to provide an accurate assessment of atheroma accumulation within the arterial wall. Here we describe how IVUS can be applied to the serial assessment of atheroma burden in response to treatment with a range of anti-atherosclerotic strategies, which has resulted in its emergence as a key technology in the evaluation and approval of novel drugs.

High amylase resistant starch to decrease stool output in people with short bowel syndrome: A pilot trial.

Short bowel syndrome (SBS) is defined as having less than 200 cm of functional small bowel. Malabsorptive diarrhoea and dehydration are difficult to manage despite medical therapy and dietary manipulations. Evidence shows that supplementing the diet with High Amylase Resistant Starch (HARS) can reduce diarrhoea from a number of causes including gastroenteritis. It is hypothesised HARS will decrease stool output via the production of short chain fatty acids and the resultant increased water reabsorption. This study aimed to determine if the addition of HARS can reduce diarrhoea in patients with SBS. METHODS: Patients with SBS with colon in continuity were recruited from the intestinal rehabilitation clinic at Austin Health. The study was a 2 week crossover trial. Each participant completed the control and the intervention (addition of 50 g HARS to usual diet). Total daily stool weight and number of bowel actions per day were compared between groups using paired t-tests. RESULTS: Eight adults (58% male, mean age 55.7 yrs) were recruited. Five participants completed the trial. Total daily stool weight was reduced in all participants when consuming HARS. Mean daily stool output was significantly decreased 1049 ± 519 g/d to 804 ± 585 g/d (p = 0.023). Number of bowel actions per day showed a trend to reduction. CONCLUSION: This study gives some support to the hypothesis that the addition of HARS into the diet of patients with short bowel syndrome reduces stool output. Longer trials are required to confirm the effect on nutritional/hydration status.

Statin therapy, LDL cholesterol, C-reactive protein, and coronary artery disease.

BACKGROUND: Recent trials have demonstrated better outcomes with intensive than with moderate statin treatment. Intensive treatment produced greater reductions in both low-density lipoprotein (LDL) cholesterol and C-reactive protein (CRP), suggesting a relationship between these two biomarkers and disease progression. METHODS: We performed intravascular ultrasonography in 502 patients with angiographically documented coronary disease. Patients were randomly assigned to receive moderate treatment (40 mg of pravastatin orally per day) or intensive treatment (80 mg of atorvastatin orally per day). Ultrasonography was repeated after 18 months to measure the progression of atherosclerosis. Lipoprotein and CRP levels were measured at baseline and follow-up. RESULTS: In the group as a whole, the mean LDL cholesterol level was reduced from 150.2 mg per deciliter (3.88 mmol per liter) at baseline to 94.5 mg per deciliter (2.44 mmol per liter) at 18 months (P<0.001), and the geometric mean CRP level decreased from 2.9 to 2.3 mg per liter (P<0.001). The correlation between the reduction in LDL cholesterol levels and that in CRP levels was weak but significant in the group as a whole (r=0.13, P=0.005), but not in either treatment group alone. In univariate analyses, the percent change in the levels of LDL cholesterol, CRP, apolipoprotein B-100, and non-high-density lipoprotein cholesterol were related to the rate of progression of atherosclerosis. After adjustment for the reduction in these lipid levels, the decrease in CRP levels was independently and significantly correlated with the rate of progression. Patients with reductions in both LDL cholesterol and CRP that were greater than the median had significantly slower rates of progression than patients with reductions in both biomarkers that were less than the median (P=0.001). CONCLUSIONS: For patients with coronary artery disease, the reduced rate of progression of atherosclerosis associated with intensive statin treatment, as compared with moderate statin treatment, is significantly related to greater reductions in the levels of both atherogenic lipoproteins and CRP.

Non-invasive imaging of global and regional cardiac function in pulmonary hypertension.

Pulmonary hypertension (PH) is a progressive illness characterized by elevated pulmonary artery pressure; however, the main cause of mortality in PH patients is right ventricular (RV) failure. Historically, improving the hemodynamics of pulmonary circulation was the focus of treatment; however, it is now evident that cardiac response to a given level of pulmonary hemodynamic overload is variable but plays an important role in the subsequent prognosis. Non-invasive tests of RV function to determine prognosis and response to treatment in patients with PH is essential. Although the right ventricle is the focus of attention, it is clear that cardiac interaction can cause left ventricular dysfunction, thus biventricular assessment is paramount. There is also focus on the atrial chambers in their contribution to cardiac function in PH. Furthermore, there is evidence of regional dysfunction of the two ventricles in PH, so it would be useful to understand both global and regional components of dysfunction. In order to understand global and regional cardiac function in PH, the most obvious non-invasive imaging techniques are echocardiography and cardiac magnetic resonance imaging (CMRI). Both techniques have their advantages and disadvantages. Echocardiography is widely available, relatively inexpensive, provides information regarding RV function, and can be used to estimate RV pressures. CMRI, although expensive and less accessible, is the gold standard of biventricular functional measurements. The advent of 3D echocardiography and techniques including strain analysis and stress echocardiography have improved the usefulness of echocardiography while new CMRI technology allows the measurement of strain and measuring cardiac function during stress including exercise. In this review, we have analyzed the advantages and disadvantages of the two techniques and discuss pre-existing and novel forms of analysis where echocardiography and CMRI can be used to examine atrial, ventricular, and interventricular function in patients with PH at rest and under stress.

Determinants of arterial wall remodeling during lipid-lowering therapy: serial intravascular ultrasound observations from the Reversal of Atherosclerosis with Aggressive Lipid Lowering Therapy (REVERSAL) trial.

BACKGROUND: Coronary plaque progression and instability are associated with expansive remodeling of the arterial wall. However, the remodeling response during plaque-stabilizing therapy and its relationship to markers of lipid metabolism and inflammation are incompletely understood. METHODS AND RESULTS: Serial intravascular ultrasound (IVUS) data from the Reversal of Atherosclerosis with Aggressive Lipid Lowering Therapy (REVERSAL) trial were obtained during 18 months of intensive versus moderate lipid-lowering therapy. In a subgroup of 210 patients, focal coronary lesions with mild luminal narrowing were identified. Lumen area, external elastic membrane (EEM) area, and plaque area were determined at the lesion and proximal reference sites at baseline and during follow-up. The remodeling ratio (RR) was calculated by dividing the lesion EEM area by the reference EEM area. The relationship between the change in remodeling, change in plaque area, lipid profile, and inflammatory markers was examined. At the lesion site, a progression in plaque area (8.9+/-25.7%) and a decrease in the RR (-3.0+/-11.2%) occurred during follow-up. In multivariable analyses, the percentage change in plaque area (P<0.0001), baseline RR (P<0.0001), baseline lesion lumen area (0.019), logarithmic value of the change in high-sensitivity C-reactive protein (P=0.027), and hypertension at baseline (P=0.014) showed a significant, direct relation with the RR at follow-up. Lesion location in the right coronary artery (P=0.006), percentage change in triglyceride levels (P=0.049), and age (P=0.037) demonstrated a significant, inverse relation with the RR at follow-up. Changes in LDL cholesterol, HDL cholesterol, and treatment group demonstrated no significant associations. CONCLUSIONS: Constrictive remodeling of the arterial wall was observed during plaque-stabilizing therapy with statin medications and appears related to their antiinflammatory effects.

Statins, high-density lipoprotein cholesterol, and regression of coronary atherosclerosis.

CONTEXT: Statins reduce low-density lipoprotein cholesterol (LDL-C) levels and slow progression of coronary atherosclerosis. However, no data exist describing the relationship between statin-induced changes in high-density lipoprotein cholesterol (HDL-C) and disease progression. OBJECTIVE: To investigate the relationship between changes in LDL-C and HDL-C levels and atheroma burden. DESIGN, SETTING, AND PATIENTS: Post-hoc analysis combining raw data from 4 prospective randomized trials (performed in the United States, North America, Europe, and Australia between 1999 and 2005), in which 1455 patients with angiographic coronary disease underwent serial intravascular ultrasonography while receiving statin treatment for 18 months or for 24 months. Ultrasound analysis was performed in the same core laboratory for all of the studies. MAIN OUTCOME MEASURE: Relationship between changes in lipoprotein levels and coronary artery atheroma volume. RESULTS: During statin therapy, mean (SD) LDL-C levels were reduced from 124.0 (38.3) mg/dL (3.2 [0.99] mmol/L) to 87.5 (28.8) mg/dL (2.3 [0.75] mmol/L) (a 23.5% decrease; P<.001), and HDL-C levels increased from 42.5 (11.0) mg/dL (1.1 [0.28] mmol/L) to 45.1 (11.4) mg/dL (1.2 [0.29] mmol/L) (a 7.5% increase; P<.001). The ratio of LDL-C to HDL-C was reduced from a mean (SD) of 3.0 (1.1) to 2.1 (0.9) (a 26.7% decrease; P<.001). These changes were accompanied by a mean (SD) increase in percent atheroma volume from 39.7% (9.8%) to 40.1% (9.7%) (a 0.5% [3.9%] increase; P = .001) and a mean (SD) decrease in total atheroma volume of 2.4 (23.6) mm3 (P<.001). In univariate analysis, mean levels and treatment-mediated changes in LDL-C, total cholesterol, non-HDL cholesterol, apolipoprotein B, and ratio of apolipoprotein B to apolipoprotein A-I were significantly correlated with the rate of atherosclerotic progression, whereas treatment-mediated changes in HDL-C were inversely correlated with atheroma progression. In multivariate analysis, mean levels of LDL-C (beta coefficient, 0.11 [95% confidence interval, 0.07-0.15]) and increases in HDL-C (beta coefficient, -0.26 [95% confidence interval, -0.41 to -0.10]) remained independent predictors of atheroma regression. Substantial atheroma regression (> or =5% reduction in atheroma volume) was observed in patients with levels of LDL-C less than the mean (87.5 mg/dL) during treatment and percentage increases of HDL-C greater than the mean (7.5%; P<.001). No significant differences were found with regard to clinical events. CONCLUSIONS: Statin therapy is associated with regression of coronary atherosclerosis when LDL-C is substantially reduced and HDL-C is increased by more than 7.5%. These findings suggest that statin benefits are derived from both reductions in atherogenic lipoprotein levels and increases in HDL-C, although it remains to be determined whether the atherosclerotic regression associated with these changes in lipid levels will translate to meaningful reductions in clinical events and improved clinical outcomes.

Effect of very high-intensity statin therapy on regression of coronary atherosclerosis: the ASTEROID trial.

CONTEXT: Prior intravascular ultrasound (IVUS) trials have demonstrated slowing or halting of atherosclerosis progression with statin therapy but have not shown convincing evidence of regression using percent atheroma volume (PAV), the most rigorous IVUS measure of disease progression and regression. OBJECTIVE: To assess whether very intensive statin therapy could regress coronary atherosclerosis as determined by IVUS imaging. DESIGN AND SETTING: Prospective, open-label blinded end-points trial (A Study to Evaluate the Effect of Rosuvastatin on Intravascular Ultrasound-Derived Coronary Atheroma Burden [ASTEROID]) was performed at 53 community and tertiary care centers in the United States, Canada, Europe, and Australia. A motorized IVUS pullback was used to assess coronary atheroma burden at baseline and after 24 months of treatment. Each pair of baseline and follow-up IVUS assessments was analyzed in a blinded fashion. PATIENTS: Between November 2002 and October 2003, 507 patients had a baseline IVUS examination and received at least 1 dose of study drug. After 24 months, 349 patients had evaluable serial IVUS examinations. INTERVENTION: All patients received intensive statin therapy with rosuvastatin, 40 mg/d. MAIN OUTCOME MEASURES: Two primary efficacy parameters were prespecified: the change in PAV and the change in nominal atheroma volume in the 10-mm subsegment with the greatest disease severity at baseline. A secondary efficacy variable, change in normalized total atheroma volume for the entire artery, was also prespecified. RESULTS: The mean (SD) baseline low-density lipoprotein cholesterol (LDL-C) level of 130.4 (34.3) mg/dL declined to 60.8 (20.0) mg/dL, a mean reduction of 53.2% (P<.001). Mean (SD) high-density lipoprotein cholesterol (HDL-C) level at baseline was 43.1 (11.1) mg/dL, increasing to 49.0 (12.6) mg/dL, an increase of 14.7% (P<.001). The mean (SD) change in PAV for the entire vessel was -0.98% (3.15%), with a median of -0.79% (97.5% CI, -1.21% to -0.53%) (P<.001 vs baseline). The mean (SD) change in atheroma volume in the most diseased 10-mm subsegment was -6.1 (10.1) mm3, with a median of -5.6 mm3 (97.5% CI, -6.8 to -4.0 mm3) (P<.001 vs baseline). Change in total atheroma volume showed a 6.8% median reduction; with a mean (SD) reduction of -14.7 (25.7) mm3, with a median of -12.5 mm3 (95% CI, -15.1 to -10.5 mm3) (P<.001 vs baseline). Adverse events were infrequent and similar to other statin trials. CONCLUSIONS: Very high-intensity statin therapy using rosuvastatin 40 mg/d achieved an average LDL-C of 60.8 mg/dL and increased HDL-C by 14.7%, resulting in significant regression of atherosclerosis for all 3 prespecified IVUS measures of disease burden. Treatment to LDL-C levels below currently accepted guidelines, when accompanied by significant HDL-C increases, can regress atherosclerosis in coronary disease patients. Further studies are needed to determine the effect of the observed changes on clinical outcome. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00240318.

Myocardial ischemic-fibrotic injury after human heart transplantation is associated with increased progression of vasculopathy, decreased cellular rejection and poor long-term outcome.

OBJECTIVES: We sought to assess the influence of peritransplant ischemia and fibrosis on the development of allograft vasculopathy, acute cellular rejection and long-term outcome. BACKGROUND: Allograft vasculopathy is a common long-term complication of cardiac transplantation. One of the potential risk factors is peritransplant allograft ischemia. METHODS: One hundred forty heart transplant recipients had baseline and one-year intravascular ultrasound analysis done to assess the progression of allograft vasculopathy. Serial endomyocardial biopsies were evaluated for cellular rejection, vascular rejection, ischemia and fibrosis. Based on histology, patients were classified into one of the following groups: nonischemic (n = 32), ischemia (n = 24), fibrosis (n = 62) or vascular rejection (n = 22). Three-color flow cytometry crossmatching (FCXM) was used to assess donor-specific human lymphocyte antigens (HLA) sensitization. Long-term outcome of patients in each group was assessed by estimating incidence of graft failure or deaths over a seven-year follow up. RESULTS: Patients in the fibrosis group had the lowest incidence of donor-specific HLA sensitization (40%, p = 0.008) and lowest average episodes of cellular rejection (1.7 +/- 1.4, p = 0.04), but they had increased coronary vasculopathy progression (change in coronary intimal thickness = 0.59 +/- 0.28 mm, p < 0.0001) and poor seven-year event-free survival (49%, p = 0.01). CONCLUSIONS: The development of fibrosis after cardiac transplantation is associated with advanced coronary vasculopathy, although a low incidence of acute cellular rejection is noted, suggesting the presence of nonimmune mechanisms in mediating the pathogenesis of allograft vasculopathy.

Effect of atorvastatin (80 mg/day) versus pravastatin (40 mg/day) on arterial remodeling at coronary branch points (from the REVERSAL study).

The effect of moderate and intensive lipid lowering on plaque progression and arterial remodeling at coronary branch points was investigated. Intensive (+1 +/- 19.6%), but not moderate (+4.1 +/- 15.1%), lipid lowering prevented an increase in the percent [corrected] plaque area at the branch points. The 2 strategies were associated with increased areas of the lumen (+7.6% to 9.4%) and external elastic membrane (+9.6% to 10.8%). In contrast, there was no significant change in plaque, lumen, and/or external elastic membrane areas at the nonbranch point site. These results suggest that intensive lipid lowering can have a dramatic effect on atheroma-prone regions and that remodeling in response to changes in plaque is a heterogenous process.

The effect of combined Angiotensin-converting enzyme inhibition and calcium antagonism on allograft coronary vasculopathy validated by intravascular ultrasound.

BACKGROUND: Hypertension is a potential risk factor for allograft coronary vasculopathy. We evaluated the efficacy of angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists, and their combined use, on the development of coronary vasculopathy in hypertensive heart transplant recipients. METHODS: Eighty-two heart transplant recipients underwent serial intravascular ultrasound (IVUS) analysis at baseline (within 1 month) and at 1 year after transplantation and were evaluated for the development of coronary vasculopathy. Patients were divided into 4 groups. Nineteen normotensive recipients received no treatment, control (Group A). Hypertensive patients were treated with either ACE inhibitors (Group B, n = 37), calcium antagonists (Group C, n = 16), or both (Group D, n = 10). RESULTS: We found a significant reduction in IVUS indices of coronary vasculopathy in heart transplant recipients who used a combination of an ACE inhibitor and a calcium antagonist compared with recipients who used either drug alone (p < 0.05). This synergistic efficacy was independent of the baseline indices evaluated in a multivariate regression analysis model and was noted despite comparable mean arterial pressure among the 3 hypertensive groups at 1 year, thus suggesting the presence of a synergistic anti-proliferative effect beyond the anti-hypertensive efficacy. CONCLUSIONS: The combined use of an ACE inhibitor and a calcium antagonist is more effective than the individual use of either drug alone on the development of coronary vasculopathy in cardiac transplant recipients. Large randomized clinical trials are warranted to evaluate such a synergistic efficacy.

Does acute cellular rejection correlate with cardiac allograft vasculopathy?

BACKGROUND: Previous studies of the association between acute cellular rejection and cardiac allograft vasculopathy (CAV) have yielded conflicting conclusions. We explored a possible association between acute cellular rejection and the extent of CAV, and we found a potential confounding variable that may obscure such an association. METHODS: We investigated 140 patients (mean age, 51 +/- 11 years) who underwent serial intravascular ultrasound examinations at baseline and at 1 year after heart transplantation to assess CAV as change in maximal intimal thickness (CMIT). Patients were classified according to the presence or absence of biopsy-proven myocardial fibrosis. We used a standard biopsy-scoring system and a novel biopsy-scoring system, developed in our institution, to assess acute cellular rejection. Using univariate analysis, we found that CMIT was not associated with acute cellular rejection in the overall patient population (n = 140). However, we observed a correlation between CMIT and acute cellular rejection (standard method, r = 0.30, p = 0.01; novel method, r = 0.51, p < 0.0001) in patients who had no evidence of ischemic injury or fibrosis in their biopsy specimens (n = 57). Step-wise multiple regression showed that the rejection score derived from our novel method was associated more closely with the CMIT than was that derived from the traditional method. CONCLUSIONS: This data indicate that the presence of myocardial fibrosis masks an actuarial association between acute cellular rejection and the development of de novo allograft vasculopathy. As previously suspected, myocardial fibrosis is a marker for non-immune-mediated graft injury independently associated with an increased incidence of CAV.

Computerized scoring of histopathology for predicting coronary vasculopathy, validated by intravascular ultrasound.

BACKGROUND: Allograft coronary vasculopathy results from a complex interplay between immunologic and non-immunologic factors. We devised a computerized biopsy scoring method based on histopathology to predict the development of coronary vasculopathy. METHODS: One hundred forty heart transplant recipients underwent serial intravascular ultrasound analysis at baseline (within 1 month) and at 1 year after transplantation and were evaluated for development of coronary vasculopathy (change in coronary maximal intimal thickness, CMIT). We evaluated serial endomyocardial biopsy specimens for cellular rejection, vascular rejection, ischemia, and fibrosis. In a mathematical model, we computed a biopsy score in each patient based on the duration and severity of histopathology. RESULTS: We found a significant correlation between biopsy score (RY) and progression of coronary vasculopathy (r = 0.54, p = 0.001). Using a sensitivity analysis method, an RY value of > or =560 predicted development of coronary vasculopathy with a sensitivity of 86%, specificity of 62%, and diagnostic accuracy of 80%. Compared with patients with low-risk biopsy scores (RY < 560, n = 37), patients with high-risk biopsy scores (RY > or = 560, n = 103) had increased progression of coronary vasculopathy (CMIT, 0.59 +/- 0.29 vs 0.19 +/- 0.10 mm, p < 0.001) and worse 7-year event-free survival (60% vs 91%, p = 0.01). CONCLUSION: The biopsy score is an effective method for predicting the development of coronary vasculopathy and for predicting outcome in cardiac transplant recipients.

Variability of area measurements obtained with different intravascular ultrasound catheter systems: Impact on clinical trials and a method for accurate calibration.

BACKGROUND: Atherosclerotic plaque burden is the major end point in ongoing progression trials. Intravascular ultrasound allows precise measurements of coronary artery dimensions. However, the variability of measurements among different catheter systems is incompletely characterized. METHODS: Intravascular ultrasound imaging was performed in a cylindric phantom with 5 sections of different, known, cross-sectional area ranging from 3.24 to 27.99 mm(2). A total of 3637 measurements with different catheter systems (Atlantis SR and Ultracross, Scimed/Boston Scientific; and Invision and Avanar, Jomed) were performed. Measurements were divided into model building and validation datasets. For each catheter, calibration models were developed. RESULTS: Overestimation and underestimation of the true cross-sectional area of up to 18% was observed with different catheter systems. Calibration equations for the different systems could be developed that predicted the true diameter and area with high statistical precision (adjusted R(2) > 0.99). CONCLUSIONS: Area measurements vary among different intravascular ultrasound catheter systems. Calibration equations can correct for these differences and allow the comparison of measurements among catheters.

Effect of intensive compared with moderate lipid-lowering therapy on progression of coronary atherosclerosis: a randomized controlled trial.

CONTEXT: Statin drugs reduce both atherogenic lipoproteins and cardiovascular morbidity and mortality. However, the optimal strategy and target level for lipid reduction remain uncertain. OBJECTIVE: To compare the effect of regimens designed to produce intensive lipid lowering or moderate lipid lowering on coronary artery atheroma burden and progression. DESIGN, SETTING, AND PATIENTS: Double-blind, randomized active control multicenter trial (Reversal of Atherosclerosis with Aggressive Lipid Lowering [REVERSAL]) performed at 34 community and tertiary care centers in the United States comparing the effects of 2 different statins administered for 18 months. Intravascular ultrasound was used to measure progression of atherosclerosis. Between June 1999 and September 2001, 654 patients were randomized and received study drug; 502 had evaluable intravascular ultrasound examinations at baseline and after 18 months of treatment. INTERVENTIONS: Patients were randomly assigned to receive a moderate lipid-lowering regimen consisting of 40 mg of pravastatin or an intensive lipid-lowering regimen consisting of 80 mg of atorvastatin. MAIN OUTCOME MEASURES: The primary efficacy parameter was the percentage change in atheroma volume (follow-up minus baseline). RESULTS: Baseline low-density lipoprotein cholesterol level (mean, 150.2 mg/dL [3.89 mmol/L] in both treatment groups) was reduced to 110 mg/dL (2.85 mmol/L) in the pravastatin group and to 79 mg/dL (2.05 mmol/L) in the atorvastatin group (P<.001). C-reactive protein decreased 5.2% with pravastatin and 36.4% with atorvastatin (P<.001). The primary end point (percentage change in atheroma volume) showed a significantly lower progression rate in the atorvastatin (intensive) group (P =.02). Similar differences between groups were observed for secondary efficacy parameters, including change in total atheroma volume (P =.02), change in percentage atheroma volume (P<.001), and change in atheroma volume in the most severely diseased 10-mm vessel subsegment (P<.01). For the primary end point, progression of coronary atherosclerosis occurred in the pravastatin group (2.7%; 95% confidence interval [CI], 0.2% to 4.7%; P =.001) compared with baseline. Progression did not occur in the atorvastatin group (-0.4%; CI -2.4% to 1.5%; P =.98) compared with baseline. CONCLUSIONS: For patients with coronary heart disease, intensive lipid-lowering treatment with atorvastatin reduced progression of coronary atherosclerosis compared with pravastatin. Compared with baseline values, patients treated with atorvastatin had no change in atheroma burden, whereas patients treated with pravastatin showed progression of coronary atherosclerosis. These differences may be related to the greater reduction in atherogenic lipoproteins and C- reactive protein in patients treated with atorvastatin.

Effect of recombinant ApoA-I Milano on coronary atherosclerosis in patients with acute coronary syndromes: a randomized controlled trial.

CONTEXT: Although low levels of high-density lipoprotein cholesterol (HDL-C) increase risk for coronary disease, no data exist regarding potential benefits of administration of HDL-C or an HDL mimetic. ApoA-I Milano is a variant of apolipoprotein A-I identified in individuals in rural Italy who exhibit very low levels of HDL. Infusion of recombinant ApoA-I Milano-phospholipid complexes produces rapid regression of atherosclerosis in animal models. OBJECTIVE: We assessed the effect of intravenous recombinant ApoA-I Milano/phospholipid complexes (ETC-216) on atheroma burden in patients with acute coronary syndromes (ACS). DESIGN: The study was a double-blind, randomized, placebo-controlled multicenter pilot trial comparing the effect of ETC-216 or placebo on coronary atheroma burden measured by intravascular ultrasound (IVUS). SETTING: Ten community and tertiary care hospitals in the United States. PATIENTS: Between November 2001 and March 2003, 123 patients aged 38 to 82 years consented, 57 were randomly assigned, and 47 completed the protocol. INTERVENTIONS: In a ratio of 1:2:2, patients received 5 weekly infusions of placebo or ETC-216 at 15 mg/kg or 45 mg/kg. Intravascular ultrasound was performed within 2 weeks following ACS and repeated after 5 weekly treatments. MAIN OUTCOME MEASURES: The primary efficacy parameter was the change in percent atheroma volume (follow-up minus baseline) in the combined ETC-216 cohort. Prespecified secondary efficacy measures included the change in total atheroma volume and average maximal atheroma thickness. RESULTS: The mean (SD) percent atheroma volume decreased by -1.06% (3.17%) in the combined ETC-216 group (median, -0.81%; 95% confidence interval [CI], -1.53% to -0.34%; P =.02 compared with baseline). In the placebo group, mean (SD) percent atheroma volume increased by 0.14% (3.09%; median, 0.03%; 95% CI, -1.11% to 1.43%; P =.97 compared with baseline). The absolute reduction in atheroma volume in the combined treatment groups was -14.1 mm3 or a 4.2% decrease from baseline (P<.001). CONCLUSIONS: A recombinant ApoA-I Milano/phospholipid complex (ETC-216) administered intravenously for 5 doses at weekly intervals produced significant regression of coronary atherosclerosis as measured by IVUS. Although promising, these results require confirmation in larger clinical trials with morbidity and mortality end points.

Clinical expert consensus document on standards for acquisition, measurement and reporting of intravascular ultrasound regression/progression studies.

Atherosclerotic cardiovascular disease is a leading cause of morbidity and mortality despite the widespread use of established medical therapies. This has prompted the search to identify new therapeutic approaches to achieve more effective prevention of cardiovascular events. Considerable interest has focused on the role of surrogate markers of therapeutic efficacy in the early evaluation of novel anti-atherosclerotic therapies. Monitoring changes in the extent of coronary atherosclerosis with intravascular ultrasound (IVUS) has been increasingly employed in clinical trials to assess progression and regression of atherosclerosis. This is based on the pivotal role that atherosclerotic plaque plays in the natural history of cardiovascular disease and the acceptance of validated arterial imaging approaches including coronary angiography and carotid intimal-medial thickness by regulatory authorities. The ability to generate high-resolution imaging of the entire thickness of the coronary artery wall permits evaluation of the entire burden of atherosclerotic plaque. In order to understand the differences, similarities, limitations and pitfalls of the IVUS technique among different academic core laboratories, a number of meetings of representatives from these groups were convened in 2007 and 2008. This document is the result of those IVUS methodology meetings that assembled experts from core laboratories to discuss standards for image acquisition, definitions, criteria, analyses, and primary and secondary endpoints.