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Biomedical subjects

Ronald J Oudiz

Publications and source records attributed to Ronald J Oudiz.

At least 19 recordsLinked to original sources
PubMed2006

Complications of right heart catheterization procedures in patients with pulmonary hypertension in experienced centers.

OBJECTIVES: This study sought to assess the risks associated with right heart catheter procedures in patients with pulmonary hypertension. BACKGROUND: Right heart catheterization, pulmonary vasoreactivity testing, and pulmonary angiography are established diagnostic tools in patients with pulmonary hypertension, but the risks associated with these procedures have not been systematically evaluated in a multicenter study. METHODS: We performed a multicenter 5-year retrospective and 6-month prospective evaluation of serious adverse events related to right heart catheter procedures in patients with pulmonary hypertension, as defined by a mean pulmonary artery pressure >25 mm Hg at rest, undergoing right heart catheterization with or without pulmonary vasoreactivity testing or pulmonary angiography. RESULTS: During the retrospective period, 5,727 right heart catheter procedures were reported, and 1,491 were reported from the prospective period, for a total of 7,218 right heart catheter procedures performed. The results from the retrospective and the prospective analyses were almost identical. The overall number of serious adverse events was 76 (1.1%, 95% confidence interval 0.8% to 1.3%). The most frequent complications were related to venous access (e.g., hematoma, pneumothorax), followed by arrhythmias and hypotensive episodes related to vagal reactions or pulmonary vasoreactivity testing. The vast majority of these complications were mild to moderate in intensity and resolved either spontaneously or after appropriate intervention. Four fatal events were recorded in association with any of the catheter procedures, resulting in an overall procedure-related mortality of 0.055% (95% confidence interval 0.01% to 0.099%). CONCLUSIONS: When performed in experienced centers, right heart catheter procedures in patients with pulmonary hypertension are associated with low morbidity and mortality rates.

Aged↗
PubMed2006

Randomized study of adding inhaled iloprost to existing bosentan in pulmonary arterial hypertension.

RATIONALE: Small, open-label studies suggest that combinations of existing therapies may be effective for pulmonary arterial hypertension (PAH). OBJECTIVE: To evaluate the safety and efficacy of adding inhaled iloprost, a prostacyclin analog, to the endothelin receptor antagonist bosentan in patients with PAH. METHODS: In a randomized, multicenter, double-blind trial, inhaled iloprost (5 mug) or placebo was added to stable monotherapy with bosentan for 12 wk. Efficacy endpoints included change from baseline in 6-min-walk distance (6-MWD), modified New York Heart Association (NYHA) functional class, hemodynamic parameters, and time to clinical worsening. MEASUREMENTS AND MAIN RESULTS: A total of 67 patients with PAH (55% idiopathic PAH, 45% associated PAH, 94% NYHA class III, and mean baseline 6-MWD of 335 m) were randomized. At Week 12, patients receiving iloprost had a mean increase in 6-MWD of 30 m (p = 0.001); placebo patients had a mean 6-MWD increase of 4 m (p = 0.69), with a placebo-adjusted difference of +26 m (p = 0.051). NYHA status improved by one class in 34% of iloprost versus 6% of placebo patients (p = 0.002). Iloprost delayed the time to clinical worsening (p = 0.0219). Improvements were noted in postinhalation placebo-adjusted change in mean pulmonary artery pressure (-8 mm Hg; p < 0.001) and pulmonary vascular resistance (-254 dyn x s x cm(-5); p < 0.001). Combination therapy was well tolerated. CONCLUSIONS: Within the limitations of a relatively small sample size, results of this study demonstrate that the addition of inhaled iloprost in patients with PAH with reduced exercise capacity on bosentan monotherapy is safe and efficacious.

Adolescent↗
PubMed2006

Noninvasive gadolinium-enhanced three dimensional computed tomography coronary angiography.

RATIONALE AND OBJECTIVES: Although the use of gadolinium (Gd)-based contrast agents for angiographic studies of abdominal aorta, renal vasculature, and digital subtraction angiography has been reported, no studies have shown their diagnostic efficacy and image quality in coronary computed tomography angiography (CTA). The aim of this study is to evaluate the image quality of Gd-based contrast agents during coronary CTA. MATERIALS AND METHODS: A phantom study was done to evaluate the attenuation of serial dilutions of Gd and iodinated agents. This study was done on a 64-slice multirow detector CT (MDCT) scanner and e-speed scanner and CT attenuation Hounsfield units (CTHU) were compared. We evaluated 35 consecutive patients who underwent Gd-enhanced CTA. CTHU of aorta was measured at first, mid, and lowest slice levels with and without contrast administration. The image quality was graded on the basis of visualization of the coronary arteries (scale I-III; III demonstrating diagnostic image quality of the distal-most vessels). In a substudy, four patients with borderline renal insufficiency underwent CTA using Gd and iodinated contrast agents admixed in a 50:50 ratio. RESULTS: The phantom study showed that enhancement of various dilutions of Gd and iodine resulted in near identical CTHU with both e-speed and 64-slice scanners (r(2) > or = 0.997). Mean CTHU with contrast at the top slice was 116 HU, at middle slice was 125 HU, and at the lower slice was 93 (111.14 +/- 22). Quality evaluation showed 2 grade III, 9 grade II, and 24 grade I images (average quality of images 1.35). Mean CTHU was 222. CONCLUSION: Gd-enhanced contrast medium provides adequate enhancement of coronary vasculature, allowing for diagnostic evaluation of coronary arteries with new CT systems. Use of newer generations of multirow detector CT scanners should further enhance the quality of images.

Adult↗
PubMed2006

Temporal trends and drug exposures in pulmonary hypertension: an American experience.

BACKGROUND: Reports have linked anorexigen intake to an increased risk of pulmonary arterial hypertension (PAH). With the rise in anorexigen use in the latter half of the last decade, we established a surveillance network within the United States to monitor temporal trends in the number of reported cases of PAH. We also studied whether use of anorexigens and other drugs differed among patients with pulmonary hypertension of different etiologies. METHODS: Newly diagnosed subjects (N = 1335) at 13 tertiary pulmonary hypertension centers were enrolled between January 1998 and June 2001. Patient-reported medication use was obtained by a telephone interview. Patients were classified as to the type of pulmonary hypertension. Poisson regression models were fitted to monthly case counts, and logistic regression methods were used to assess the association between type of pulmonary hypertension and medication use. RESULTS: The average monthly number of reported cases of PAH and other categories of pulmonary hypertension did not change over the study period. Fenfluramine or dexfenfluramine use during the 5 years before the time of the interview was preferentially associated with PAH. Fenfluramine/dexfenfluramine use was particularly common in cases referred but found not to have pulmonary hypertension. CONCLUSIONS: No epidemic of anorexigen-related PAH was evident during the study period. As persons who had taken fenfluramine or dexfenfluramine were particularly likely to be referred for evaluation of pulmonary hypertension, it is unlikely that the failure to detect an anorexigen-induced rise in primary pulmonary hypertension was because of underascertainment. The association between fenfluramine derivatives and PAH is consistent with the risk elevations previously reported.

Adolescent↗
PubMed2005

Cardiopulmonary exercise testing and six-minute walk correlations in pulmonary arterial hypertension.

In a clinical trial of 178 patients with pulmonary arterial hypertension, treatment improved the 6-minute walk (6MW) distance but not the peak VO2. To clarify this discrepancy, we examined the exercise data from all study sites. Patients received either the endothelin receptor antagonist sitaxsentan or placebo and underwent serial 6MW and cardiopulmonary exercise testing (CPET). In 518 pairs of body weight-adjusted and unadjusted 6MW and CPET data, the correlation between 6MW and peak VO2 was 0.48. In the 4 sites with the highest overall correlation at baseline (r = 0.62 compared with 0.46 for the other 19 sites, p = 0.04), the correlations at baseline (0.66) and at week 12 (0.65) were similar (p = 0.90). However, the correlation increased significantly from baseline (0.34) to week 12 (0.54, p = 0.0005) for the other 19 sites. The correlations between weight-adjusted 6MW distance and peak VO2 for all centers (0.76) were significantly higher than the unadjusted correlations (0.48, p < 0.0001). Improvement in the correlations over time between the 6MW and CPET data at less-experienced sites was most consistent with improved technical skill with increasing experience. Weight adjustment of the 6MW improved its correlation with peak VO2. In conclusion, in future multicenter trials, CPET expertise should be validated at all sites before subject enrollment.

Adolescent↗
PubMed2005

Detection of small vessels with electron beam computed tomographic angiography using 1.5 and 3 mm collimator protocols.

OBJECTIVES: To evaluate the effect of scanner collimation on the ability to detect small cardiac vessels using electron beam CT coronary angiography (EBA). MATERIALS AND METHODS: EBA scans from 40 patients who underwent study on two separate occasions with 3 mm (initial scan) and 1.5 mm (follow-up scan) collimation protocols were analyzed. Vessels of <2 mm in diameter were identified. RESULTS: The 1.5 mm collimation allowed 3-D visualization of 129 vessels<2 mm in diameter, while 3 mm collimation only allowed visualization of 89 vessels (p<0.001). The right coronary artery branches and distal LAD segments though were not displayed satisfactorily in almost half of the 3-D studies with either protocol. CONCLUSIONS: There was significant improvement in detection of small cardiac vessels with a 1.5 mm collimation EBA protocol compared to a 3 mm protocol. Both protocols though were insufficient for reliable visualization of the right coronary artery branches and distal LAD segments.

Coronary Angiography↗
PubMed2005

Comparison of coronary artery calcium screening image quality between C-150 and e-Speed electron beam scanners.

RATIONALE AND OBJECTIVE: The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). MATERIALS AND METHODS: Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. RESULTS: With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P < .001) as well as decreased noise values (24.3 versus 32.0 HU, P < .001). CONCLUSION: Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.

Artifacts↗
PubMed2005

Coronary venous imaging with electron beam computed tomographic angiography: three-dimensional mapping and relationship with coronary arteries.

BACKGROUND: The coronary venous system can provide vascular access for diagnostic and therapeutic procedures. Visualization of the coronary veins and their relationship to other cardiac structures may play an important role in facilitating these procedures. We sought to assess the ability of electron beam computed tomographic angiography (EBCTA) to characterize 3-dimensional (3-D) coronary venous anatomy. METHODS: Two hundred thirty-one consecutive EBCTA coronary studies were analyzed. The coronary venous system was mapped and analyzed using 2- and 3-D images with definition of diameter and angulations of branch vessels and distance from CS os. RESULTS: The coronary sinus (CS), great cardiac, middle cardiac, left ventricular (LV) anterior interventricular, LV marginal, LV posterior, left atrial, and right atrial veins were visualized in 100%, 100%, 100%, 100%, 78%, 81%, 6%, and 8% of the studies, respectively, with definition of diameter and angulations of branch vessels and distance from CS os. There was a significant linear correlation between CS diameter and right atrial end systolic volume (R = 0.244, n = 81, P < .05). No significant correlation existed between CS os diameter and other cardiac size or function parameters. The 3-D spatial arrangements between the coronary veins and the coronary arteries in relation to the epicardium were able to be defined, on the basis of the vessel closer to the epicardium in overlapping segments. CONCLUSIONS: EBCTA can provide 3-D visualization of most components of the coronary venous system and definition of the spatial relationships with coronary arteries. EBCTA may potentially serve as a useful noninvasive tool for coronary venous imaging for procedures involving coronary veins, such as resynchronization therapy.

Adult↗
PubMed2005

The role of exercise testing in the management of pulmonary arterial hypertension.

The assessment of exercise capacity is of critical importance in the evaluation and management of patients with moderate to severe pulmonary arterial hypertension (PAH). The practicing clinician uses various exercise modalities in evaluating and managing patients with PAH. These include the 6-minute walk test (6MW), cardiopulmonary exercise testing, and exercise echocardiography. The change in exercise capacity appears to parallel other clinical indicators of disease severity, such as survival, hemodynamics, and time to clinical worsening. Exercise testing can aid the clinician in outlining the nature of a patient's exercise limitation, noninvasively assessing disease severity, establishing prognosis, and evaluating the response to therapy. Additional work must be done to validate the utility of measuring exercise capacity in patients with less severe PAH.

Echocardiography↗
PubMed2005

End-tidal PCO2 abnormality and exercise limitation in patients with primary pulmonary hypertension.

OBJECTIVES: Primary pulmonary hypertension (PPH) is a pulmonary vasculopathy resulting in exercise intolerance, usually due to dyspnea. We hypothesized that ventilation is increased during exercise in PPH relative to normal because the ventilated lung is underperfused, cardiac output increase is restricted, and arterial hypoxemia may develop. Our aim was to determine the size of the reduction in end-tidal Pco(2) (Petco(2)) as a reflection of the abnormality in ventilatory efficiency and ventilatory drive in PPH patients. METHODS: We performed cardiopulmonary exercise testing (CPET) in 52 PPH patients. All had hemodynamic measurements to confirm the diagnosis of PPH. A subgroup of 29 patients who underwent right-heart catheterization within 50 days of CPET were studied to compare their CPET responses to resting hemodynamics. Nine healthy volunteers matched for age and gender served as CPET control subjects. RESULTS: In PPH patients, the percentage of predicted peak oxygen uptake (Vo(2)) correlated significantly with mean pulmonary artery pressure (mPAP) [r = - 0.59, p = 0.0007, n = 29]. Petco(2) values at rest, anaerobic threshold (AT), and peak Vo(2) were proportionately reduced as percentage of predicted peak Vo(2) decreased (r = 0.66 to 0.72, p < 0.0001, n = 52). Petco(2) values at rest, AT, and peak Vo(2) were also reduced as mPAP increased (r = - 0.51 to - 0.53, p < 0.005, n = 29). In contrast to normal subjects in whom Petco(2) increased from rest to AT, Petco(2) decreased in PPH patients, except for two patients with mild PPH in whom there was no change. Also, Petco(2) increased rather than decreased further at the start of recovery, in contrast to normal. Although usually normal at rest, oxyhemoglobin saturation decreased during exercise in most PPH patients. CONCLUSIONS: In patients with PPH, Petco(2) at rest and exercise is significantly reduced in proportion to physiologic disease severity. The range of values is unusually low. Furthermore, the directional changes of Petco(2) during exercise and early recovery are in the opposite direction of normal.

Adult↗
PubMed2004

End points and clinical trial designs in pulmonary arterial hypertension: clinical and regulatory perspectives.

To date, randomized controlled clinical trials performed in pulmonary arterial hypertension (PAH) have been relatively short-term studies involving mainly patients with advanced disease. The primary end points in these trials have addressed exercise capacity, usually by using the 6-min walk test. Although this approach is still warranted in future trials assessing new treatments, it is likely that the focus will shift toward trials of longer duration, involving patients with less advanced disease, and that different drugs and drug-combination regimens will be compared. In such trials, it is possible that a composite of markers indicating clinical deterioration (e.g., hospitalization for right heart failure, the requirement for the introduction of an alternative treatment, and predefined indicators of worsening exercise tolerance) may be more useful as primary end points. Quality of life will become a very important issue; however, appropriate quality-of-life questionnaires for PAH have yet to be developed. In addition, hemodynamics will likely remain valuable as secondary end points, but future clinical trials should include hemodynamics obtained both during exercise and at rest. Finally, cardiopulmonary exercise testing, echocardiographic studies, and biochemical parameters, such as brain natriuretic peptide or troponin T, may also prove useful as secondary end points in the future.

Clinical Trials as Topic↗
PubMed2004

Micrococcus-associated central venous catheter infection in patients with pulmonary arterial hypertension.

STUDY OBJECTIVES: To determine the incidence of catheter-related infection in patients with pulmonary arterial hypertension (PAH) receiving epoprostenol (EPO), and to note an etiologic role for Micrococcus spp, which is rarely reported as a pathogen in the medical literature. DESIGN: Observational study. SETTING: Two PAH specialty treatment centers, Harbor-UCLA Medical Center (Torrance, CA), and the College of Physicians and Surgeons, Columbia University (New York, NY). PATIENTS: A total of 192 patients with PAH receiving continuous therapy with IV EPO. INTERVENTIONS: From 1987 to 2000, 192 patients with PAH received infusions of EPO via central venous catheter. Catheter care included regular dressing changes with dry gauze using a sterile procedure, without the use of flushes. Patients were asked to report on known infections and treatments, and symptoms. All infections were verified by a telephone call to the patient, care provider, and microbiology laboratory whenever possible. MEASUREMENTS AND RESULTS: There were 335,285 catheter days (mean +/- SD, 1,325 +/- 974 catheter days). There were 88 clinical catheter infections with 51 blood culture-positive infections, necessitating catheter removal in 38 instances. The following pathogens were isolated: Staphylococcus aureus (25); Micrococcus spp (14); mixed flora (3); coagulase-negative Staphylococcus spp (2); Corynebacterium spp (2); Serratia marcessens (1); Enterobacter spp (1); Pseudomonas aeruginosa (1); enterococci (1); and unidentified Gram-positive cocci (1). The catheter infection rate was 0.26 per 1,000 catheter days. CONCLUSIONS: The use of long-term therapy with continuous EPO appears to be associated with a low incidence of catheter-related infections. Micrococcus spp were the second most common etiologic agent. Caregivers managing patients with PAH must be aware of the risk of catheter infection, as it may contribute to the morbidity and mortality associated with the use of EPO. When isolated, Micrococcus spp should not be viewed as a contaminant, but rather as a true pathogen that may require therapeutic intervention.

Adult↗
PubMed2004

Treprostinil, a prostacyclin analogue, in pulmonary arterial hypertension associated with connective tissue disease.

STUDY OBJECTIVES: To assess the efficacy and safety of continuous subcutaneous infusion of treprostinil, a stable prostacyclin analogue, for treating pulmonary arterial hypertension (PAH) in patients with connective tissue disease (CTD). DESIGN: Two multicenter, randomized, double-blind, placebo-controlled, prospective trials of treprostinil vs placebo in 470 patients with PAH. PATIENTS: A subset of 90 patients with PAH and CTD, including systemic lupus erythematosus, diffuse scleroderma, limited scleroderma, and mixed CTD/overlap syndrome. INTERVENTIONS: Patients received either treprostinil (initiated at 1.25 ng/kg/min, and titrated upward) or placebo via continuous subcutaneous infusion. The maximum dose of treprostinil allowed was 22.5 ng/kg/min. MEASUREMENTS: Six-minute walk (6MW) distance and dyspnea-fatigue scores were determined at baseline, and at 6 weeks and 12 weeks. Hemodynamic measures were obtained at baseline and at 12 weeks. RESULTS: At baseline, most patients had New York Heart Association class III symptoms. The mean baseline 6MW distance was 289 m (range, 60 to 448 m). The mean dose of treprostinil at week 12 was 8.4 ng/kg/min (range, 1.25 to 17.5 ng/kg/min). After 12 weeks, the change in cardiac index from baseline was + 0.2 +/- 0.08 L/min/m(2) in the treprostinil group and - 0.07 +/- 0.07 L/min/m(2) in the placebo group (p = 0.007). The pulmonary vascular resistance index decreased by 4 +/- 2 U x m(2) in the treprostinil group and increased by 1 +/- 1 U x m(2) in the placebo group (p = 0.006). The placebo-corrected median improvement from baseline in 6MW distance was 25 m in treprostinil-treated patients (p = 0.055); this improvement appeared to be dose related. Dyspnea fatigue scores also improved in the treprostinil group compared with the placebo group (p = 0.014). Adverse events included infusion site pain and typical side effects related to prostaglandins, and were tolerated by most patients. CONCLUSIONS: Continuous subcutaneous infusion of treprostinil in patients with PAH associated with CTD improved exercise capacity, symptoms of PAH, and hemodynamics.

Adolescent↗
PubMed2003

Pulmonary function in primary pulmonary hypertension.

OBJECTIVES: The study was done to ascertain the degree to which abnormalities in resting lung function correlate with the disease severity of patients with primary pulmonary hypertension (PPH). BACKGROUND: Patients with PPH are often difficult to diagnose until several years after the onset of symptoms. Despite the seriousness of the disorder, the diagnosis of PPH is often delayed because it is unsuspected and requires invasive measurements. Although PPH often causes abnormalities in resting lung function, these abnormalities have not been shown to be statistically significant when correlated with other measures of PPH severity. METHODS: Resting lung mechanics and diffusing capacity for carbon monoxide DL(CO) were assessed in 79 patients whose findings conformed to the classical diagnostic criteria of PPH and who had no evidence of secondary causes of pulmonary hypertension. These findings were correlated with severity of disease as assessed by cardiac catheterization, New York Heart Association (NYHA) class, and cardiopulmonary exercise testing. RESULTS: When PPH patients were first evaluated at our referral clinic, the DL(CO) and lung volumes were decreased in approximately three-quarters and one-half, respectively. The decreases in DL(CO), and to a lesser extent lung volumes, correlated significantly with decreases in peak oxygen uptake (reflecting maximum cardiac output), peak oxygen pulse (reflecting maximum stroke volume), and anaerobic threshold (reflecting sustainable exercise capacity) and higher NYHA class. CONCLUSIONS: Patients with PPH commonly have abnormalities in lung mechanics and DL(CO) levels that correlate significantly with disease severity. These measurements can be useful in evaluating patients with unexplained dyspnea and fatigue.

Adult↗
PubMed2003

Measurement of the RT interval on ECG records during electron-beam CT.

RATIONALE AND OBJECTIVES: The R wave of the electrocardiogram is used widely as a trigger for cardiac imaging. This study was designed to determine the optimal interval between the R wave and end systole for triggering of electron-beam computed tomography (CT) in a group of patients with various heart rates who are undergoing assessment for coronary artery calcification. MATERIALS AND METHODS: A total of 862 consecutive asymptomatic patients referred for screening with electron-beam CT for coronary artery calcification were enrolled in the study. Patients' R-R, RT, and PR intervals were measured by using the software of the CT console computer. Correlation coefficients were computed and linear regression analyses were performed for all intervals measured. Results were analyzed according to patient age (three subgroups), sex (two subgroups), and heart rate (nine subgroups). Separate formulas for calculating the length of RT intervals in men and in women were developed. RESULTS: After correction for heart rate, a significant difference was found in mean RT and PR intervals between women and men, with the mean intervals in women being longer (P < .001). No significant difference was found in these intervals within the three age-defined subgroups (< or = 40, 41-60, and >60 years; P > .05). However, significant negative correlations were found between heart rates and the lengths of all measured intervals. The results of statistical analysis indicate that most of the variation in the R-R interval with different heart rates occurred in diastole and that the duration of systole was relatively constant. CONCLUSION: For optimal cardiac imaging, triggering should take place in late systole, avoiding the RT interval variability that occurs in diastole.

Adult↗
PubMed2003

Efficacy and safety of treprostinil: an epoprostenol analog for primary pulmonary hypertension.

Intravenous epoprostenol is currently FDA approved for management of primary pulmonary hypertension, but it requires intravenous infusion and is associated with adverse effects. The objective of this study was to evaluate the effects of an epoprostenol analog, treprostinil, for management of pulmonary hypertension. Ten tertiary care academic institutions with pulmonary hypertension programs participated in these pilot trials. In the first trial, intravenous epoprostenol and intravenous treprostinil were compared. In the second trial, intravenous treprostinil and subcutaneous treprostinil were compared. In the third trial, subcutaneous treprostinil was compared with placebo infusion during an 8-week period. Intravenous epoprostenol and intravenous treprostinil resulted in a similar reduction in pulmonary vascular resistance acutely (22% and 20%, respectively). Intravenous treprostinil and subcutaneous treprostinil also demonstrated comparable short-term decrease in pulmonary vascular resistance (23% and 28%, respectively). The placebo-controlled 8-week trial demonstrated a mean improvement of 37 +/- 17 m as measured by the 6-minute walk distance in patients receiving treprostinil compared with a 6 +/- 28 m reduction in those receiving placebo. There were trends toward an improvement in cardiac index and pulmonary vascular resistance index in the treprostinil group. Subcutaneous treprostinil has favorable hemodynamic effects when given acutely and in the short term. Treprostinil can be given safely to an ambulatory patient with a novel subcutaneous delivery pump system.

Adolescent↗