A Novel Method for Assessing Cardiac Output With the Use of Oxygen Circulation Time.

BACKGROUND: We investigated whether a simple breath hold would yield dynamic oxygen (O2) saturation change and whether the derived circulation time would be useful in assessing cardiac function. METHODS AND RESULTS: Patients undergoing right heart catheterization for clinical indications (n = 48), including heart failure (HF; n = 24), were prospectively recruited. Each subject was instructed to hold their breath for 20-40 seconds. Lung to finger circulation time (LFCT), defined as the time from the point of rebreathing to nadir O2 desaturation, was correlated with cardiac output. Among 48 subjects recruited, 37 manifested ≥3% O2 desaturation allowing for an LFCT measurement. Mean LFCT was 38.5 ± 17.5 seconds (range 18.9-94.7 s). LFCT in patients with a clinical diagnosis of HF was significantly longer than those without (45.9 ± 19.9 s vs 31.5 ± 11.5 s; P = .01). Overall, the LFCT was inversely correlated with cardiac output (Fick: r = -0.56; P < .001 [n = 37]; thermodilution: r = -0.6; P = .001 [n = 27]). CONCLUSIONS: LFCT is prolonged in low cardiac output. LFCT is a novel method that may be useful to noninvasively assess cardiac function in HF.

Posttraumatic stress disorder and incident heart failure among a community-based sample of US veterans.

OBJECTIVES: We investigated the association between posttraumatic stress disorder (PTSD) and incident heart failure in a community-based sample of veterans. METHODS: We examined Veterans Affairs Pacific Islands Health Care System outpatient medical records for 8248 veterans between 2005 and 2012. We used multivariable Cox regression to estimate hazard ratios and 95% confidence intervals for the development of heart failure by PTSD status. RESULTS: Over a mean follow-up of 7.2 years, veterans with PTSD were at increased risk for developing heart failure (hazard ratio [HR] = 1.47; 95% confidence interval [CI] = 1.13, 1.92) compared with veterans without PTSD after adjustment for age, gender, diabetes, hyperlipidemia, hypertension, body mass index, combat service, and military service period. Additional predictors for heart failure included age (HR = 1.05; 95% CI = 1.03, 1.07), diabetes (HR = 2.54; 95% CI = 2.02, 3.20), hypertension (HR = 1.87; 95% CI = 1.42, 2.46), overweight (HR = 1.72; 95% CI = 1.25, 2.36), obesity (HR = 3.43; 95% CI = 2.50, 4.70), and combat service (HR = 4.99; 95% CI = 1.29, 19.38). CONCLUSIONS: Ours is the first large-scale longitudinal study to report an association between PTSD and incident heart failure in an outpatient sample of US veterans. Prevention and treatment efforts for heart failure and its associated risk factors should be expanded among US veterans with PTSD.

Multicenter urethroplasty outcomes for urethral stricture disease for patients with neurogenic bladder or bladder dysfunction requiring clean intermittent catheterization.

BACKGROUND: Our objective is to better comprehend treatment considerations for urethral stricture disease (USD) in patients requiring long-term clean intermittent catheterization (CIC). Patient characteristics, surgical outcomes and complications are unknown in this population. METHODS: Six members of the Trauma and Urologic Reconstruction Network of Surgeons (TURNS) participated in a prospective (2009 to present) and retrospective (prior to 2009) database recording patient demographics, surgical approach and outcomes. We included all patients undergoing urethroplasty who perform CIC. Descriptive statistics were used to analyze results. RESULTS: A total of 37 patients with 39 strictures were included. Bladder dysfunction was characterized as detrusor failure in 35% and neurogenic etiology in 65%. Median stricture length was 3 cm (IQR: 1.5-5.5) with 28% repaired with dorsal onlay buccal mucosal graft, 26% excision and primary anastomosis, 8% dorsal inlay, 8% ventral and dorsal, 8% flap based 8% non-transecting and 15% other. Functional success was 90%: 4 patients required DVIU or dilation due to recurrence, with 2 of those ultimately requiring repeat urethroplasty. 86% of patients returned to CIC; no patients reported new pad use for urinary leakage after urethroplasty. During a median follow-up period of 3.1 years (IQR: 1.0-5.3), no patients underwent urinary diversion. CONCLUSIONS: Urethroplasty is suitable, safe and effective for patients dependent on CIC suffering from USD. The effect of continual CIC on long-term outcomes remains uncertain.

Impact of 30 Day Readmission After Left Ventricular Assist Device Implantation.

Early readmission (within 30 days) after left ventricular assist device (LVAD) implantation might be a marker for increased mortality. We retrospectively reviewed the records of 277 adults who underwent continuous-flow LVAD implantation from 2005 through 2015 at our institution. The baseline characteristics of patients who were (versus were not) readmitted within 30 days after LVAD implantation were compared. To assess the impact of 30 day readmission on long-term survival, we used multivariate Cox regression. We also compared the cardiac transplant rate between the two groups. Of the 277 patients, 217 (78.3%) underwent LVAD implantation as a bridge-to-transplant; 76 (27.4%) of the 277 were readmitted within 30 days. The most common reason for readmission was volume overload (23.6%), followed by gastrointestinal bleeding (15.8%). Male gender, previous smoking, a higher baseline creatinine level, higher Model for End Stage Liver Disease Excluding INR (MELD-XI) score, and postoperative gastrointestinal bleeding or stroke were each associated with 30 day readmission. In our final multivariate model, increased mortality was also associated with 30 day readmission (hazard ratio, 1.60; 95% confidence interval, 1.1-2.5). Among the 217 bridge-to-transplant patients, the cardiac transplant rate was similar between the two groups: 18.7 transplants per patient-year among those who were readmitted within 30 days versus 19.7 transplants per patient-year among those who were not (p = 0.26). Among our study patients, 30 day readmission after LVAD implantation was frequent and was associated with increased mortality. It is currently unclear whether the general health of those patients was a factor and whether efforts to reduce 30 day readmission would favorably affect longer-term patient outcomes.

Impact of Postoperative Liver Dysfunction on Survival After Left Ventricular Assist Device Implantation.

BACKGROUND: Liver dysfunction in left ventricular assist device (LVAD) recipients is common both before and after implantation. Postoperative liver dysfunction (PLD) develops in some LVAD recipients without preoperative liver dysfunction. The aim of this study was to assess clinical outcomes in such patients. METHODS: Records of all patients undergoing implantation of a HeartMate II (HM II, St. Jude Medical, Inc, Minneapolis, MN) LVAD at a single center at the University of Minnesota from January 2005 through June 2014 were analyzed. PLD was defined by hypertransaminasemia or hyperbilirubinemia, or both, during the hospitalization for LVAD implantation. RESULTS: During the study period, 284 patients underwent HM II implantation. Excluded from analysis were 14 recipients with preoperative liver dysfunction. In the final cohort (n = 270), there were no major difference in preoperative characteristics among those patients with versus without PLD. PLD developed in 129 (47.8%) recipients: 16 (12.4%) had isolated hypertransaminasemia (group I), 76 (58.9%) had isolated hyperbilirubinemia (group II), and 37 (28.7%) had combined hypertransaminasemia and hyperbilirubinemia (group III). Group III LVAD recipients had significantly greater rates of 30-day, 90-day, and 1-year mortality, along with significantly higher transfusion requirements and higher rates of renal replacement therapy, prolonged ventilation, and vasopressor use. Moreover, their mortality risk was significantly higher than that of PLD-free LVAD recipients (hazard ratio, 4.6; 95% confidence interval, 2.1 to 10.1; p < 0.001). CONCLUSIONS: Isolated hyperbilirubinemia is common after LVAD implantation. In this study, it was not associated with an increase in early or midterm postoperative mortality. However, postoperative combined transaminasemia and hyperbilirubinemia was associated with a significant increase in early and midterm morbidity and mortality. Further research into the pathogenesis of post-LVAD PLD is necessary.

Aortic insufficiency in continuous-flow left ventricular assist device support patients is common but does not impact long-term mortality.

BACKGROUND: Aortic insufficiency (AI) is a significant long-term complication of continuous-flow left ventricular assist device (CF-LVAD) implantation. We sought to evaluate its impact on clinical outcomes and mortality in CF-LVAD recipients. METHODS: We retrospectively analyzed 237 patients implanted with HeartMate II CF-LVADs at our institution from June 2005 through June 2013. We evaluated recipients' baseline characteristics and annual echocardiograms, grading AI severity as either none, trace, mild, moderate or severe. Only moderate or severe AI was considered clinically significant. Recipients who underwent concomitant aortic valve surgery or who had undergone previous prosthetic aortic valve implantation were excluded. RESULTS: Moderate or severe AI occurred in 32 (15.2%) patients. Risk factors that significantly affected the development of AI included older age at the time of implantation, female gender, longer duration of LVAD support and destination therapy designation. Freedom from moderate or severe AI was 94%, 76% and 65% of patients at 1, 3 and 5 years, respectively. Overall cohort survival based on Kaplan-Meier analysis was 78%, 59% and 42% at 1, 3 and 5 years, respectively. There was no difference in survival between recipients who developed significant AI and those who did not (log-rank test, p = 0.73). CONCLUSIONS: In this large, single-institution study, the overall rate of AI was low, but increased in frequency with longer duration of LVAD support. Although AI development remains a concern for patients on long-term CF-LVAD support, AI development does not appear to impact long-term mortality.

A Decade of Experience With Continuous-Flow Left Ventricular Assist Devices.

The use of continuous-flow left ventricular assist devices (CF-LVADs) has revolutionized the landscape of mechanical circulatory support for patients with heart failure. Clinical trials are already testing the next generation of CF-LVADs. In this study, our objective was to review our long-term experience with the current generation of CF-LVADs, specifically, the HeartMate (HM) II (Thoratec Corp, Pleasanton, CA). In this single-center retrospective analysis, we evaluated the records of 278 consecutive patients who underwent a total of 302 HM II placements from June 2005 through June 2014. We excluded 11 patients from our final study group, who had previously undergone placement of a HM XVE that failed. We divided the remaining 267 patients into 3 equal groups of 89 patients each, by time period: group 1, June 2005 through May 2009; group 2, June 2009 through January 2012; and group 3, February 2012 through June 2014. To examine differences in survival between our 3 groups, we used time-to-event analysis, including the Kaplan-Meier method. To examine secondary outcomes (including stroke, hemolysis, gastrointestinal bleeding, pump thrombus, and transplant), we used one-way analysis of variance. For our final study group of 267 patients, the total follow-up time was 479.01 patient-years (median, 469 days). The mean age of patients was 57 years; 81.4% were male. In all, 209 (78.9%) patients underwent HM II placement as a bridge to transplant; 58 (21.1%), as destination therapy (DT). The overall survival rate was 94% at 30 days, 77% at 1 year, 65% at 2 years, 60% at 3 years, 50% at 4 years, and 48% at 5 years. In bridge to transplant patients, the survival rate was 78% at 1 year and 66% at 2 years; in DT patients, 70% and 60%. In group 1 patients, the survival rate was 94% at 30 days, 64% at 1 year, and 48% at 2 years; in group 2, 93%, 88%, and 76%; and in group 3, 94%, 77%, and 73% (P = 0.003). In the later years of our study period, from June 2009 onwards (ie, in groups 2 and 3), we noted a statistically significant increase in HM II placement as DT, a reduction of driveline infections, increasing pump exchange, increasing hemolysis, a reduced frequency of transplants, and an improved survival rate (as compared with the earlier group 1). The HM II has favorably influenced the outcomes of patients with end-stage heart failure, yet major complications still limit their survival. Improving compatibility between the pump and the individual host patient, enhancing anticoagulation strategies, and developing a totally implantable pump might further reduce complications thereby improving survival times and allowing CF-LVAD placement to be a true long-term alternative to a heart transplant.

Trends and Outcomes of Pulmonary Arterial Hypertension-Related Hospitalizations in the United States: Analysis of the Nationwide Inpatient Sample Database From 2001 Through 2012.

IMPORTANCE: Recent trends and outcomes of pulmonary arterial hypertension (PAH)-related hospitalization in adults in the United States are unknown. OBJECTIVE: To examine the characteristics of PAH-related hospitalizations. DESIGN, SETTING, AND PARTICIPANTS: We analyzed the National Inpatient Sample database for all adult patients (≥18 years old) with PAH as the principal discharge diagnosis from January 1, 2001, through December 31, 2012. MAIN OUTCOMES AND MEASURES: We analyzed the temporal trends in hospitalization rate, hospital charges, in-hospital mortality, length of hospitalization, and comorbidities pertaining to PAH-related hospitalizations. We also evaluated the predictors of in-hospital mortality and length of hospitalizations. RESULTS: The number of PAH-related hospitalizations per year in adults decreased significantly from 2001 through 2012 (3177 vs 1345, P for trend <.001). However, the mean hospital charge per admission increased 2.7-fold from 2001 through 2012 ($29 507 vs $79 607, P for trend <.001). There was a significant increase in each of these associated comorbid conditions: diabetes (4.6%-7.8%), hypertension (5.1%-17.1%), coronary artery disease (15.6%-22.3%), chronic obstructive pulmonary disease (14.4%-20.1%), anemia (12.4%-20.4%), cardiac dysrhythmias (21.7%-29.0%), congestive heart failure (40.7%-56.1%), acute (5.9%-20.1%) or chronic kidney disease (1.1%-16.4%), fluid and electrolyte imbalance (18.9%-35.3%), pneumonia (4.4%-6.3%), cardiogenic shock (0.5%-1.5%), and acute respiratory failure (4.3%-20.8%) from 2001 through 2012. The length of hospitalization increased (mean [SE], 7.0 [0.5] days in 2001 vs 7.6 [0.6] days in 2012, P for trend = .009), but in-patient mortality remained unchanged (7.8% [1.1%] in 2001 vs 6.3% [1.7%] in 2012, P for trend = .54). Admission to a teaching hospital (ß coefficient for length of hospitalization, 2.0; 95% CI, 1.3-1.6; odds ratio [OR] for mortality, 1.5; 95% CI, 1.1-2.1), cardiac dysrhythmias (ß coefficient, 1.8; 95% CI, 1.1-2.6; OR, 1.8; 95% CI, 1.4-2.4), acute kidney injury (ß coefficient, 5.0; 95% CI, 3.9-6.1; OR, 2.3; 95% CI, 1.7-3.2), acute cerebrovascular accident (ß coefficient, 6.6; 95% CI, 1.9-11.3; OR, 6.7; 95% CI, 2.1-21.1), and acute respiratory failure (ß coefficient, 6.2; 95% CI, 5.1-7.4; OR, 5.6; 95% CI, 4.2-7.5) were associated with increased length of hospitalization and in-hospital mortality. Congestive heart failure (OR, 1.7; 95% CI, 1.3-2.2), cardiogenic shock (OR, 5.4; 95% CI, 2.7-10.9), and fluid and electrolyte imbalance (OR, 1.9; 95% CI, 1.5-2.4) were associated with increased in-hospital mortality but not length of hospitalization. CONCLUSIONS AND RELEVANCE: Analyses of temporal changes in PAH care reveal a significant decrease in PAH-related hospitalizations in the United States, but hospital charges have increased substantially and are increasingly being borne by Medicare. In-hospital mortality remains unchanged, but length of hospitalization has increased. This study should help identify the characteristics of patients with PAH that are associated with increased risk of in-hospital mortality and longer length of hospitalization.

Safety and Outcomes of Capsule Endoscopy in Patients with Left Ventricular Assist Device: a Single-Center Retrospective Case Series.

Obscure gastrointestinal bleeding (GIB) in patients with continuous-flow left ventricular assist devices (CF-LVAD) is common. Capsule endoscopy (CE) can be used in the diagnosis of obscure GIB. Safety and outcomes of CE in patients with CF-LVAD are unknown. The aim is to define the safety and outcomes of CE in this population. Paitents with CF-LVAD undergoing CE at a single center between 2007 and 2014 were retrospectively reviewed. Thirty-four CE studies were performed. Positive CE occurred in 19 studies. No clinically significant cardiac events occurred. Medical intervention was the most common management strategy. Rebleeding after CE occurred in 10 patients. Patients with active bleeding or lesions such as arteriovenous malformations (AVM) incurred a higher risk of rebleeding, transfusion, and repeated endoscopy. CE is safe in patients with CF-LVAD. The risk of rebleeding was more common in patients with active bleeding or AVM lesions although this result did not reach statistical significance.

Gastrointestinal Bleeding during Continuous-Flow Left Ventricular Assist Device Support is Associated with Lower Rates of Cardiac Transplantation.

Gastrointestinal bleeding (GIB) remains a significant problem after continuous-flow left ventricular assist device (CF-LVAD) implantation. We hypothesized that the subsequent need for blood transfusions in patients with GIB may reduce rates of cardiac transplantation. We performed a retrospective review of 232 patients implanted with the HeartMate II (HM II) CF-LVAD from June 2005 through May 2013 at our center to determine risk factors for GIB and assess its effect on cardiac transplantation. Over a total LVAD follow-up time of 364 person-years, 62 GIB episodes occurred in 49 patients (27%), for an event rate of 0.45 gastrointestinal bleeds/patient-year of LVAD support. Women made up 15% of our cohort, yet contributed 29% of the GIB (p = 0.06). Survival at 6 month, 1 year, and 2 years was not statistically different in patients who developed GIB and those who did not (77% vs 78%, 74% vs 71%, and 61% vs 54%, respectively). In transplant-eligible patients, GIB was associated with a 27% lower rate of cardiac transplantation (rate ratio 0.73, p < 0.05). Although the mechanism behind this finding is unclear, GIB appears to be linked to higher transfusion rates, which may cause the development of subsequent allosensitization.

Stroke After Left Ventricular Assist Device Implantation: Outcomes in the Continuous-Flow Era.

BACKGROUND: Left ventricular assist devices (LVADs) are increasingly used in patients with heart failure. To study the impact of stroke on clinical outcomes after continuous-flow (CF-) LVAD implantation, we evaluated our single-center experience. METHODS: From 2006 to 2013, we implanted the HeartMate II CF-LVAD in 230 patients. We used standard statistical methods to evaluate our results. RESULTS: Of our study group, 185 patients (80.4%) received the CF-LVAD as a bridge to transplantation. Strokes occurred in a total of 39 patients (17%), an incidence rate of 0.064 strokes per person-year: 19 (48.7%) were embolic, and 20 (51.3%) were hemorrhagic. The stroke-free rate at 6 months after HeartMate II implantation was 92.6%, at 12 months, 89.6%, and at 24 months, 86.1%. Baseline demographic characteristics did not differ significantly, except that stroke patients had a lower incidence of coronary artery disease (p = 0.004) and prior cardiac surgery (p = 0.001). We noted a trend toward an increased risk of stroke in patients with CF-LVAD-related infections (p = 0.053). The survival rate in stroke (versus stroke-free) patients at 6 months was 84.6% (versus 84.2%); at 12 months, 71.8% (versus 81.6%); and at 24 months, 53.9% (versus 74.7%; p = 0.0019). During a median follow-up time of 761 days, mortality risk in stroke patients was 2.01 times that of stroke-free patients (hazard ratio = 2.01; p = 0.004). CONCLUSIONS: Stroke while on CF-LVAD support was associated with significant mortality. To reduce the risk of stroke, it is essential to further elucidate risk factors, to optimize anticoagulation, and to further understand the impact of LVAD-related infections.

The Contribution of Tobacco Use to High Health Care Utilization and Medical Costs in Peripheral Artery Disease: A State-Based Cohort Analysis.

BACKGROUND: Tobacco use is an important preventable cause of peripheral artery disease (PAD) and a major determinant of adverse clinical outcomes. OBJECTIVES: This study hypothesized that tobacco use by PAD patients would be associated with higher health care utilization and associated costs. METHODS: We conducted a retrospective, cross-sectional study using 2011 claims data from the largest Minnesota health plan. The total cohort included individuals with 12 months of continuous enrollment and ≥ 1 PAD-related claim. Tobacco cessation pharmacotherapy billing codes were queried in a subgroup with pharmacy benefits. Outcomes were total costs, annual proportion of members hospitalized, and primary discharge diagnoses. RESULTS: A PAD cohort of 22,203 was identified, comprising 1,995 (9.0%) tobacco users. A subgroup of 9,027 with pharmacy benefits included 1,158 (12.8%) tobacco users. The total cohort experienced 22,220 admissions. The pharmacy benefits subgroup experienced 8,152 admissions. Within 1 year, nearly one-half the PAD tobacco users were hospitalized, 35% higher than nonusers in the total cohort (p < 0.001) and 30% higher in the subgroup (p < 0.001). In both cohorts, users were more frequently admitted for peripheral or visceral atherosclerosis (p < 0.001), acute myocardial infarction (p < 0.001), and coronary heart disease (p < 0.05). Observed costs in the total cohort were $64,041 for tobacco users versus $45,918 for nonusers. Costs for tobacco users also were consistently higher for professional and facility-based care, persisting after adjustment for age, sex, comorbidities, and insurance type. CONCLUSIONS: Tobacco use in PAD is associated with substantial increases in PAD-related hospitalizations, coronary heart disease and PAD procedures, and significantly greater costs. The results suggest that immediate provision of tobacco cessation programs may be especially cost effective.

Echocardiographic Ramp test for continuous-flow left ventricular assist devices: do loading conditions matter?

OBJECTIVES: This study investigated whether continuous AI and/or elevated mean arterial pressure (MAP) were associated with false positive results for flow obstruction in echocardiographic ramp speed tests in patients with a continuous-flow left ventricular assist device. BACKGROUND: Failure to reduce the left ventricular end-diastolic diameter (LVEDD) with increasing device speeds in a ramp test is predictive of pump obstruction. Aortic insufficiency (AI) or increased MAP can diminish the ability to unload the left ventricle. METHODS: LVEDD was plotted against device speed, and a linear function slope was calculated. A flat LVEDD slope (≥-0.16) was considered abnormal (suggestive of obstruction). Ramp test results were compared in patients with or without either AI or increased MAP at baseline speed, and receiver-operator characteristic (ROC) curves were constructed for predictors of device obstruction. Device thrombosis was confirmed by direct visualization of clot at explantation or on inspection by the manufacturer. RESULTS: Of 78 ramp tests (55 patients), 36 were abnormal (18 true positive, 18 false positive), and 42 were normal (37 true negative, 5 false negative). In patients with AI, LVEDD slope was -0.14 ± 0.17, which was consistent with device obstruction (vs. -0.25 ± 0.11 in patients without AI; p < 0.001), despite no difference in mean lactate dehydrogenase concentration between the 2 groups (1,301 ± 1,651 U/l vs. 1,354 ± 1,365 U/l; p = 0.91). Area under the ROC curve (AUC) for LVEDD slope was 0.76 and improved to 0.88 after removal of patients with AI from the study. LVEDD slope in patients with MAP ≥85 mm Hg was similar to that for device obstruction (-0.18 ± 0.07) and was abnormal in 6 of the 12 ramp tests performed. Combining LVEDD slope with lactate dehydrogenase concentration increased the AUC to 0.96 as an indicator of device obstruction. CONCLUSIONS: Abnormal loading conditions due to AI or elevated MAP may result in false positive ramp tests.

Anti-factor Xa and activated partial thromboplastin time measurements for heparin monitoring in mechanical circulatory support.

OBJECTIVES: This study investigated the relationship between anti-factor Xa (anti-FXa) and activated partial thromboplastin time (aPTT) for monitoring intravenous unfractionated heparin (IV-UFH) in patients with continuous-flow left ventricular assist devices (CF-LVADs). BACKGROUND: CF-LVADs have become mainstream therapy for patients with advanced heart failure. Thromboembolic events, device thrombosis, and bleeding continue to be a challenge with this technology. Adequate anticoagulation is required to prevent these adverse events. METHODS: A prospective study of consecutive patients implanted with a CF-LVAD was conducted. Paired samples were considered concordant if aPTT values fell into expected ranges for subtherapeutic, therapeutic, and supratherapeutic anti-FXa levels. Heparin dosing was on the basis of anti-Xa levels. RESULTS: A total of 340 paired values from 38 patients were evaluated. Anti-FXa and aPTT were discordant in 253 samples (74.4%), with a high degree of variability in aPTT for any given anti-FXa level (r(2) = 0.57). Results were discordant in 104 samples (63.8%) from patients undergoing bridging therapy with warfarin and in 149 samples (84.2%) from patients with device obstruction and/or hemolysis (p < 0.001). The most common pattern of discordance was a supratherapeutic aPTT value despite a therapeutic anti-FXa level (49.1% for bridging vs. 75.8% for device obstruction and/or hemolysis; p < 0.001). CONCLUSIONS: Levels of aPTT were disproportionately prolonged relative to the corresponding anti-FXa levels in CF-LVAD patients, particularly those with device obstruction. Hemolysis and warfarin administration may falsely elevate aPTT, resulting in overestimation of heparin concentration and under-anticoagulation. Use of aPTT and anti-FXa to guide heparin therapy may lead to different estimates of heparin concentration in the same patient.

ß-blocker therapy is not associated with adverse outcomes in patients with pulmonary arterial hypertension: a propensity score analysis.

BACKGROUND: The safety of ß-blockers in patients with isolated right ventricular failure because of pulmonary arterial hypertension (PAH) is unclear. METHODS AND RESULTS: We studied 564 PAH patients (total cohort) referred to our center from 1982 to 2013. Propensity score-matching was used to match pairs of PAH patients with and without ß-blocker use (matched cohort). We compared all-cause mortality between the groups in the total cohort and the matched cohort using bootstrap validation, Kaplan-Meier, and Cox proportional hazard analyses. Seventy-one of the 564 patients in the total cohort were on ß-blockers. They were older, had higher prevalence of comorbidities, and were more often on diuretics, digoxin, and angiotensin converting enzyme inhibitors. The severity of PAH and right ventricular failure was similar between those with and without ß-blocker use. After propensity matching, 63 patients with ß-blocker use were compared with 51 patients without ß-blocker use. During a median follow-up time of 4.8 years, there were 339 (60%) deaths in the total cohort and 70 deaths (61%) in the matched cohort. There was no difference in absolute mortality between those with and without ß-blockers (P=0.71). ß-Blocker use was not associated with increased all-cause mortality in the total cohort after adjusting for propensity score (adjusted hazard ratio, 1.0; 95% confidence interval, 0.7-1.5) and in the matched cohort (hazard ratio, 1.2; 95% confidence interval, 0.8-2.0). CONCLUSIONS: There was no statistically significant difference in long-term mortality between propensity score-matched pairs of PAH patients with and without ß-blocker use. These findings need further validation in prospective clinical trials.