Hyperbaric oxygen therapy for systemic gas embolism after hydrogen peroxide ingestion.

BACKGROUND: Hydrogen peroxide is a commonly available product and its ingestion has been demonstrated to produce in vivo gas bubbles, which can embolize to devastating effect. OBJECTIVE: We report two cases of hydrogen peroxide ingestion with resultant gas embolization, one to the portal system and one cerebral embolus, which were successfully treated with hyperbaric oxygen therapy (HBO), and review the literature. CASE REPORT: Two individuals presented to our center after unintentional ingestion of concentrated hydrogen peroxide solutions. Symptoms were consistent with portal gas emboli (Patient A) and cerebral gas emboli (Patient B), which were demonstrated on imaging. They were successfully treated with HBO and recovered without event. CONCLUSIONS: As demonstrated by both our experience as well as the current literature, HBO has been used to successfully treat gas emboli associated with hydrogen peroxide ingestion. We recommend consideration of HBO in any cases of significant hydrogen peroxide ingestion with a clinical picture compatible with gas emboli.

The Effect of Stepping Back From the X-Ray Table on Operator Radiation Exposure.

ABSTRACT: Background: Nearly all radiation safety courses teach that scatter radiation around the x-ray table falls with the inverse of the distance from the imaging site. Humans, however, are complex x-ray reflectors and the application of the inverse square law to clinical imaging is only assumed. Methods: We measured scatter radiation at two positions where staff commonly stand around the x-ray table. Using an anthropomorphic human phantom, human and pig cadavers, and a glass sphere, we measured scatter radiation levels in each position, and then 2- and 3-fold the distance from the imaging site. We compared the measured scatter radiation to that predicted by the common inverse square law and a more detailed geometric inverse square law. Results: In all but the glass sphere, scatter radiation was much higher below the table (68-74% of all scatter radiation, depending on model and position) than above the table (26-32% of scatter radiation, p < 0.01). Scatter radiation fell with increasing distance from the table, but above the table both inverse square laws significantly over-estimated the benefit of stepping back (19-93% overestimation by geometric inverse square law at 2-fold distance, 14-46% at 3-fold). In addition, a pelvis in the phantom appeared to cause significant scatter radiation field anomalies at the angiographer position. Conclusion: Stepping back from the table does not reduce scatter radiation levels as much as the inverse square law predicts. The geometric inverse square law best predicts the reduction in scatter radiation below the table, but above the table it too overestimates the benefit of stepping back. The irregularity of the scatter radiation field should be taken into account by scatter radiation shielding systems.

Intra-cardiopulmonary resuscitation hypothermia with and without volume loading in an ischemic model of cardiac arrest.

BACKGROUND: We investigated the effects of intra-cardiopulmonary resuscitation (CPR) hypothermia with and without volume loading on return to spontaneous circulation and infarction size in an ischemic model of cardiac arrest. METHODS AND RESULTS: Using a distal left anterior descending artery occlusion model of cardiac arrest followed by resuscitation with a total of 120 minutes of occlusion and 90 minutes of reperfusion, we randomized 46 pigs into 5 groups and used myocardial staining to define area at risk and myocardial necrosis. Group A had no intervention. Immediately after return of spontaneous circulation, group B received surface cooling with cooling blankets and ice. Group C received intra-CPR 680+/-23 mL of 28 degrees C 0.9% normal saline via a central venous catheter. Group D received intra-CPR 673+/-26 mL of 4 degrees C normal saline followed by surface cooling after return of spontaneous circulation. Group E received intra-CPR and hypothermia after return of spontaneous circulation with an endovascular therapeutic hypothermia system placed in the right atrium and set at a target of 32 degrees C. Intra-CPR volume loading with room temperature (group C) or iced saline (group D) significantly (P<0.05) decreased coronary perfusion pressure (group C, 12.8+/-4.78 mm Hg; group D, 14.6+/-9.9 mm Hg) compared with groups A, B, and E (20.6+/-8.2, 20.1+/-7.8, and 21.3+/-12.4 mm Hg). Return of spontaneous circulation was significantly improved in group E (9 of 9) compared with groups A plus B and C (10 of 18 and 1 of 8). The percent infarction to the area at risk was significantly reduced with intra-CPR hypothermia in groups D (24.3+/-4.2%) and E (4+/-3.4%) compared with groups A (72+/-5.1%) and B (67.3+/-4.2%). CONCLUSIONS: Intra-CPR hypothermia significantly reduces myocardial infarction size. Elimination of volume loading further improves outcomes.

Ischemic cardiac complications following G-CSF.

Granulocyte-colony stimulating factor (G-CSF) is commonly used in bone marrow transplant donors to increase the number of circulating progenitor cells. G-CSF has also been studied following myocardial infarction, but concern has been raised about the risks of G-CSF administration in patients with coronary artery disease. We present two cases of ischemic cardiac complications that are likely to be related to administration of G-CSF and provide a contemporary overview of the literature on the cardiovascular risks of G-CSF.

Impact of Genitourinary Injuries on Patients Requiring an Emergency Laparotomy for Trauma.

Introduction In patients having emergency abdominal surgery for trauma, the presence of urologic injury tends to increase mortality and morbidity. Methods This retrospective study evaluated patients requiring emergency surgery for abdominal trauma at a Level 1 Trauma Center over 30 years (1980-2010). Special attention was given to patients with concomitant genitourinary (GU) injuries. Results Of 1105 patients requiring an emergency laparotomy for trauma, 242 (22%) had urologic injuries including kidney 178 (16%), ureter 47 (4%), and bladder 46 (4%). Of the 242 patients, 50 (20%) died early (<48 hours) and 13 (5%) died later, primarily due to infection. A concept of "seven deadly signs" of hypoperfusion was developed. In patients with GU injuries, the presence of any deadly sign of hypoperfusion increased the mortality rate from 4% (6/152) to 63% (56/90), p<0.001. Of the 53 patients having a nephrectomy, 36 (68%) had one or more deadly signs and 27 (75%) died. Of 17 without deadly signs, only 2 (12%) died (p=0.001). Of 167 GU patients receiving blood, 59 (35%) developed infection vs 3/75(4%) in those receiving no blood (p<0.001). Conclusions The presence of deadly signs of severe injury and hypoperfusion on admission was the major factor determining mortality. With a severely injured kidney plus any deadly signs of hypoperfusion, special efforts should be made to avoid a nephrectomy.

Transcatheter Aortic Valve Replacement With the HLT Meridian Valve.

BACKGROUND: While most self-expanding transcatheter valves are repositionable, only one fully retrievable valve is currently available. The Meridian valve is a new self-expanding valve with full retrievability properties. The objective of our study was to evaluate the early feasibility, preliminary safety, and efficacy of transcatheter aortic valve replacement with the HLT Meridian valve (HLT, Inc). METHODS: This was a multicenter early feasibility study including patients with severe aortic stenosis at high surgical risk undergoing transfemoral transcatheter aortic valve replacement with the 25-mm Meridian valve. All serious adverse events were adjudicated by an independent clinical events committee according to Valve Academic Research Consortium-2 criteria. Echocardiography data were assessed by an independent echocardiography core laboratory. RESULTS: A total of 25 patients (mean age, 85±6 years; 80% of men) were included. The valve was successfully implanted in 22 (88%) patients (annulus too large and extreme horizontal aorta in 2 and 1 unsuccessful cases, respectively). Valve retrieval because of an initial nonadequate positioning was attempted and successfully performed in 10 (40%) patients. Echocardiography post-transcatheter aortic valve replacement showed a low mean residual gradient (10±4 mm Hg) and the absence of moderate-severe aortic regurgitation (none-trace and mild aortic regurgitation in 76% and 24% of patients, respectively). Mortality at 30 days was 8%, with no cases of disabling stroke, valve embolization, or major/life-threatening bleeding complications. At 6-month follow-up, the cumulative mortality rate was 12%, with no changes in echocardiographic parameters and no cases of valve dysfunction. The majority of patients (89%) were in New York Heart Association class I-II at 6 months. CONCLUSIONS: Transcatheter aortic valve replacement with the Meridian valve was feasible and associated with acceptable early and 6-month clinical results. Valve retrieval after full valve deployment was successfully performed in all attempted cases, and valve performance was excellent, with low residual gradients, no cases of moderate-severe aortic regurgitation, and none-trace residual aortic regurgitation in the majority of patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02838680 (RADIANT-Canada); NCT02799823 (RADIANT-US).

Gastric injury increases infections in trauma patients.

Some physicians feel gastric injury is not a significant contributing factor to the adverse outcome of trauma patients, but rather a marker of epigastric injury. We hypothesized the addition of a gastric injury to multiple injured trauma patients would increase infection rate. We conducted a retrospective study comparing 450 consecutive patients with full-thickness gastric injury with 983 patients without gastric injury during the same time period. Infection rate in patients with gastric injury was 44 per cent (200 of 455) and significantly higher than 36 per cent (357 of 983) seen without gastric injury (P = 0.006). Logistic regression revealed gastric injury was an independent risk factor for infection controlling for age, Injury Severity Scale, gender, mechanism of injury, shock, and associated injuries (P = 0.047). Requiring a transfusion, Injury Severity Scale, colon injury, age, pancreas injury, and emergency department shock were also independent risk factors for developing an infection. The addition of a gastric injury to a trauma patient appears to increase the risk for infection.

The clinical evaluation of the CADence device in the acoustic detection of coronary artery disease.

The noninvasive detection of turbulent coronary flow may enable diagnosis of significant coronary artery disease (CAD) using novel sensor and analytic technology. Eligible patients (n = 1013) with chest pain and CAD risk factors undergoing nuclear stress testing were studied using the CADence (AUM Cardiovascular Inc., Northfield MN) acoustic detection (AD) system. The trial was designed to demonstrate non-inferiority of AD for diagnostic accuracy in detecting significant CAD as compared to an objective performance criteria (sensitivity 83% and specificity 80%, with 15% non-inferiority margins) for nuclear stress testing. AD analysis was blinded to clinical, core lab-adjudicated angiographic, and nuclear data. The presence of significant CAD was determined by computed tomographic (CCTA) or invasive angiography. A total of 1013 subjects without prior coronary revascularization or Q-wave myocardial infarction were enrolled. Primary analysis was performed on subjects with complete angiographic and AD data (n = 763) including 111 subjects (15%) with severe CAD based on CCTA (n = 34) and invasive angiography (n = 77). The sensitivity and specificity of AD were 78% (p = 0.012 for non-inferiority) and 35% (p < 0.001 for failure to demonstrate non-inferiority), respectively. AD results had a high 91% negative predictive value for the presence of significant CAD. AD testing failed to demonstrate non-inferior diagnostic accuracy as compared to the historical performance of a nuclear stress OPC due to low specificity. AD sensitivity was non-inferior in detecting significant CAD with a high negative predictive value supporting a potential value in excluding CAD.

Post-traumatic hypotension: should systolic blood pressure of 90-109 mmHg be included?

It is generally accepted that patients with a systolic blood pressure (SBP)<90 mmHg are in "shock" and have a worse prognosis than patients with a higher SBP. Our objective was to determine if patients with a SBP of 90-109 mmHg have a worse outcome than patients with a higher SBP following trauma. Patients with gastric, small bowel, and/or diaphragm injuries were identified retrospectively through the trauma database from 1980-2003. All 2071 patients underwent emergent laparotomy at an urban, level one trauma center. The mortality rate of patients with a SBP of 90-109 mmHg in the ED or OR was 5% (17/354) and significantly higher than the 1% (12/1020) mortality seen in patients with a SBP of 110 mmHg or greater (P<0.001). The average length of stay of patients with a SBP of 90-109 mmHg was 15+/-14 days and was significantly longer than the 11+/-11 days seen in patients with a higher SBP. If the SBP was 90-109 mmHg, the infection rate was 39% (131/340), and this was significantly higher than the 22% (219/1016) infection rate seen in patients with higher SBP (P<0.001). Trauma patients with a systolic blood pressure of 109 mmHg or below are at increased risk for morbidity and mortality following trauma. Patients with a systolic blood pressure of 90-109 mmHg following trauma should be considered as a special group requiring aggressive resuscitation and surgery. Early operative control of hemorrhage in these patients can reduce mortality and infection.

Daptomycin versus vancomycin for complicated skin and skin structure infections: clinical and economic outcomes.

STUDY OBJECTIVE: To assess the effect of daptomycin compared with vancomycin on the clinical and economic outcomes in patients with complicated skin and skin structure infections. DESIGN: Prospective, open-label study. SETTING: Level 1 trauma center in Detroit, Michigan. PATIENTS: Fifty-three adult patients with complicated skin and skin structure infections at risk for methicillin-resistant Staphylococcus aureus (MRSA) infection who were treated with daptomycin and a matched cohort of 212 patients treated with vancomycin. INTERVENTION: Patients in the prospective arm received intravenous daptomycin 4 mg/kg every 24 hours for at least 3 days but not more than 14 days. Historical controls received at least 3 days of vancomycin dosed to achieve trough concentrations of 5-20 microg/ml. MEASUREMENTS AND MAIN RESULTS: Outcomes evaluated included blinded assessments of clinical resolution, duration of therapy, and costs. The most common diagnoses were cellulitis (31%), abscess (22%), and both cellulitis with abscess (37%). Microbiology differed significantly between groups, with S. aureus found in 27 patients (51%) in the daptomycin group and 167 patients (79%) in the vancomycin group and MRSA in 22 (42%) and 159 (75%), respectively (p<0.001). The proportions of patients with clinical improvement or resolution of their infections on days 3 and 5 were 90% versus 70% and 98% versus 81% in the daptomycin versus vancomycin groups, respectively (p<0.01 for both comparisons), and 100% at the end of therapy in both groups. Among patients with complete resolution of their infections (41 patients [77%] with daptomycin vs 89 patients [42%] with vancomycin, p<0.05), median duration of intravenous therapy was 4 and 7 days, respectively, (p<0.001), and hospital costs were $5027 and $7552 (p<0.001). CONCLUSIONS: Patients receiving daptomycin achieved more rapid resolution of symptoms and clinical cure and had a decreased duration of inpatient therapy compared with those receiving vancomycin. This study suggests that daptomycin is a cost-effective alternative to vancomycin for complicated skin and skin structure infections.

Factors affecting prognosis in patients with gastric trauma.

Morbidity and mortality after gastric injury is usually the result of associated injuries. The authors conducted a retrospective study of 544 consecutive patients with gastric trauma requiring emergency surgery. Blunt injuries had the highest mortality and length of stay. The mortality of a proximal stomach injury was 43 per cent (9 of 21) and was significantly higher than the 19 per cent mortality seen in patients with more distal injuries (P < 0.01). The majority of gastric injuries were closed primarily (492 of 544 or 90%). The patients requiring more than a primary repair had a higher mortality (22 of 52 or 42% vs. 87 of 492 or 18%; P < 0.001), required more blood (16+/-16 U vs. 6+/-11 U; P < 0.001), had an increased rate of surgical site infections (17 of 52 or 33% vs. 75 of 492 or 15%; P = 0.001), and had an increased length of stay (20+/-30 days vs. 13+/-18 days; P = 0.024). There were 22 patients with an isolated gastric injury, and all of these patients survived. Patients with an associated arterial injury had the highest mortality (49%) and highest incidence of shock (64%). Patients with colon and gastric injuries had the highest (48 of 176 or 52%) surgical site infection rate. Isolated gastric injury is rare, but is associated with low morbidity and mortality. The mechanism of injury, location of injury, and type of repair used all affect patient outcomes with gastric injury.

A novel approach to diagnosing coronary artery disease: acoustic detection of coronary turbulence.

Atherosclerotic disease within coronary arteries causes disruption of normal, laminar flow and generates flow turbulence. The characteristic acoustic waves generated by coronary turbulence serve as a novel diagnostic target. The frequency range and timing of microbruits associated with obstructive coronary artery disease (CAD) have been characterized. Technological advancements in sensor, data filtering and analytic capabilities may allow use of intracoronary turbulence for diagnostic and risk stratification purposes. Acoustic detection (AD) systems are based on the premise that the faint auditory signature of obstructive CAD can be isolated and analyzed to provide a new approach to noninvasive testing. The cardiac sonospectrographic analyzer, CADence, and CADScore systems are early-stage, investigational and commercialized examples of AD systems, with the latter two currently undergoing clinical testing with validation of accuracy using computed tomography and invasive angiography. Noninvasive imaging accounts for a large percentage of healthcare expenditures for cardiovascular disease in the developed world, and the growing burden of CAD will disproportionately affect areas in the developing world. AD is a portable, radiation-free, cost-effective method with the potential to provide accurate diagnosis or exclusion of significant CAD. AD represents a model for digital, miniaturized, and internet-connected diagnostic technologies.

Coronary Artery Disease in Patients With Out-of-Hospital Refractory Ventricular Fibrillation Cardiac Arrest.

BACKGROUND: The prevalence of coronary artery disease (CAD) among patients with refractory out-of-hospital (OH) ventricular fibrillation (VF)/ventricular tachycardia (VT) cardiac arrest is unknown. OBJECTIVES: The goal of this study was to describe the prevalence and complexity of CAD and report survival to hospital discharge in patients experiencing refractory VF/VT cardiac arrest treated with a novel protocol of early transport to a cardiac catheterization laboratory (CCL) for extracorporeal life support (ECLS) and revascularization. METHODS: Between December 1, 2015, and December 1, 2016, consecutive adult patients with refractory OH VF/VT cardiac arrest requiring ongoing cardiopulmonary resuscitation were transported by emergency medical services to the CCL. ECLS, coronary angiography, and percutaneous coronary intervention were performed, as appropriate. Functionally favorable survival to hospital discharge (Cerebral Performance Category 1 or 2) was determined. Outcomes in a historical comparison group were also evaluated. RESULTS: Sixty-two (86%) of 72 transported patients met emergency medical services transport criteria. Fifty-five (89%) of the 62 patients met criteria for continuing resuscitation on CCL arrival; 5 had return of spontaneous circulation, 50 received ECLS, and all 55 received coronary angiography. Forty-six (84%) of 55 patients had significant CAD, 35 (64%) of 55 had acute thrombotic lesions, and 46 (84%) of 55 had percutaneous coronary intervention with 2.7 ± 2.0 stents deployed per patient. The mean SYNTAX score was 29.4 ± 13.9. Twenty-six (42%) of 62 patients were discharged alive with Cerebral Performance Category 1 or 2 versus 26 (15.3%) of 170 in the historical comparison group (odds ratio: 4.0; 95% confidence interval: 2.08 to 7.7; p < 0.0001). CONCLUSIONS: Complex but treatable CAD was prevalent in patients with refractory OH VF/VT cardiac arrest who also met criteria for continuing resuscitation in the CCL. A systems approach using ECLS and reperfusion seemed to improve functionally favorable survival.

Vascular endothelial growth factor modulates contractile response in microvascular lung pericytes.

BACKGROUND: Pericytes are capillary support cells that may play a role in regulating permeability by their contractile responses. Vascular endothelial growth factor (VEGF) may play a role in the increased permeability found in sepsis and other inflammatory conditions. The purpose of this study was to evaluate the role of VEGF in regulating pericyte contraction. METHODS: Rat microvascular lung pericytes were isolated according to previously described methods and cultured on collagen gel matrices. Cells were exposed to VEGF (10, 100, and 1000 pg/mL) for varying time periods (0, 10, 30, 60, and 120 minutes). The gels were released and their contractile responses digitally quantified. RESULTS: At all doses, VEGF induced initial pericyte relaxation (contraction 85% to 90% of controls; P < .001). This was followed-up by increased and sustained contraction (107% to 120% of controls; P < .01). CONCLUSIONS: VEGF modifies the contractile response of microvascular lung pericytes. This mechanism may play a role in the increased permeability demonstrated in inflammatory states.

Audible Coronary Artery Stenosis.

OBJECTIVE: Hemodynamically significant coronary artery stenoses generate turbulent blood flow patterns that manifest as intracoronary murmurs. This study aims to evaluate the performance of modern acoustic detection of these murmurs by acoustic signals captured from patients undergoing gold standard comparative coronary angiography. METHODS: We prospectively studied 156 patients undergoing elective coronary angiography, excluding those with acute coronary syndrome, prior chest surgery, or significant valvular disease. Acoustic signals were captured before arterial access. Angiographic degree of stenosis in each coronary artery was graded blinded to clinical and acoustic data. Acoustic data were analyzed blinded to clinical and angiographic data, categorizing subjects as "normal," "diseased," or "inconclusive." Of 156 patients examined, 123 generated analyzable data. RESULTS: Angiographically significant stenosis (≥50%) prevalence was 52% (18%, 23%, 11% with 1-, 2-, 3-vessel disease, respectively). Acoustic detection sensitivity and specificity for stenosis ≥50% in any vessel were 0.70 and 0.80, respectively (negative predictive value, 0.71; positive predictive value, 0.79). Acoustic detection optimally identified stenosis ≥50% with an area under the curve of 0.75. For stenosis ≥50% in major vessels only (left main, proximal-mid left anterior descending, proximal-mid circumflex, proximal-mid right coronary), prevalence was 46%; sensitivity and specificity were 0.72 and 0.76, respectively (negative predictive value, 0.76; positive predictive value, 0.72; area under the curve, 0.76). CONCLUSIONS: Acoustic signal patterns and modern analysis techniques may be used to identify intracoronary murmurs generated by hemodynamically significant coronary artery stenoses in all major vessels. Further investigation is warranted to compare the clinical performance of this modality with current noninvasive approaches that evaluate patients at risk for atherosclerotic and obstructive coronary artery disease.

Impact of inappropriate initial antibiotics in critically ill surgical patients with bacteremia.

BACKGROUND: Bloodstream infections in critically ill patients are associated with mortality as high as 60% and a prolonged hospital stay. We evaluated the impact of inappropriate antibiotic therapy (IAAT) in a critically ill surgical cohort with bacteremia. METHODS: This retrospective study evaluated adults with intensive care unit admission greater than 72 hours and bacteremia. Two groups were evaluated: appropriate antibiotic therapy (AAT) vs IAAT. RESULTS: In 72 episodes of bacteremia, 57 (79%) AAT and 15 (21%) IAAT, mean age was 54 ± 17 years and APACHE II of 17 ± 8. Time to appropriate antibiotics was longer for IAAT (3 ± 5 IAAT vs 1 ± 1 AAT days, P = .003). IAAT was seen primarily with Acinetobacter spp (33% IAAT vs 9% AAT, P = .01) and Enterococcus faecium (26% IAAT vs 7% AAT, P = .03). If 2 or more bacteremic episodes occurred, Acinetobacter spp. was more likely, 32% vs 2%, P = .001. CONCLUSIONS: AAT selection is imperative in critically patients with bacteremia to reduce the significant impact of inappropriate selection. Repeated episodes of bacteremia should receive special attention.

Hydromorphone vs fentanyl for epidural analgesia and anesthesia.

BACKGROUND: Epidural analgesia/anesthesia is used during surgery because it dramatically relieves pain and attenuates the stress response. Because limited data exist regarding the relative merits of hydromorphone (HM) and fentanyl (FENT), the objective was to determine which was more safe and effective. METHODS: Prospective case-matched, observational study evaluated elective surgery patients: 30 HM and 60 FENT. Variables were measured perioperatively. RESULTS: Of the 90 patients, mean age was 52 years; simplified acute physiology score was 26 ± 10; and American Society of Anesthesiologists score was 2.4 HM vs 2.7 FENT, P = .03. HM patients were more apt to be excessively sedated (16% HM vs 1% FENT, P = .007) and have poor mental unresponsiveness (6% HM vs 0% FENT, P = .04). The incidence of hypotension was not different, 76% HM vs 80% FENT, not significant. CONCLUSIONS: In a closely case-matched population, FENT caused less excessive sedation and unresponsiveness. FENT patients had better intraoperative urine output and tended to have less repeated episodes of hypotension.

Reduced myocardial perfusion reserve and transmural perfusion gradient in heart transplant arteriopathy assessed by magnetic resonance imaging.

OBJECTIVES: The goal of this study was to detect transplant arteriopathy (Tx-CHD) by a reduced myocardial perfusion reserve (MPR) and resting endomyocardial/epimyocardial perfusion ratio (Endo/Epi ratio). BACKGROUND: Transplant arteriopathy often lacks clinical symptoms and is the reason for frequent surveillance angiography in heart transplant (Tx) recipients. Magnetic resonance perfusion imaging (MRPI) allows noninvasive assessment of transmural and selective endomyocardial and epimyocardial perfusion. METHODS: Fifteen healthy volunteers (controls) and three groups (A, B, C) of Tx recipients were included. In controls and patients, MPR (hyperemic/resting perfusion) and Endo/Epi ratio were determined with MRPI after injection of gadolinium-diethylenetriamine pentaacetic acid at rest and during hyperemia (intravenous adenosine). Group A (n = 10) had no left ventricular (LV) hypertrophy and/or prior rejection, while patients in group B (n = 10) had at least one of these characteristics. Patients in group A and B had a normal coronary angiogram and a coronary flow reserve (CFR) of > or =2.5 (CFR = hyperemic/resting blood flow). Group C (n = 7) had Tx-CHD diagnosed by angiography and a reduced CFR (<2.5). RESULTS: In group C, MPR (1.7 +/- 0.5) and Endo/Epi ratio (1.1 +/- 0.2) were significantly reduced compared with controls (4.2 +/- 0.7 and 1.6 +/- 0.3; both p < 0.0001), group A (3.6 +/- 0.7 and 1.6 +/- 0.2; both p < 0.0001) and B (2.7 +/- 0.9, p < 0.01 and 1.4 +/- 0.1, p < 0.04). Transplant arteriopathy can be excluded by an MPR of >2.3 with sensitivity and specificity of 100% and 85%. If LV hypertrophy and prior rejection are excluded, Tx-CHD can be excluded by an Endo/Epi ratio of >1.3 with 100% and 80%. CONCLUSIONS: Magnetic resonance perfusion imaging detects Tx-CHD by a decreased MPR. After exclusion of LV hypertrophy and prior rejection, resting Endo/Epi ratio alone might be sufficient to indicate Tx-CHD.