Association Between Claims-Defined Frailty and Outcomes Following 30 Versus 12 Months of Dual Antiplatelet Therapy After Percutaneous Coronary Intervention: Findings From the EXTEND-DAPT Study

Background Frailty is rarely assessed in clinical trials of patients who receive dual antiplatelet therapy (DAPT) after percutaneous coronary intervention. This study investigated whether frailty defined using claims data is associated with outcomes following percutaneous coronary intervention, and if there is a differential association in patients receiving standard versus extended duration DAPT. Methods and Results Patients ≥65 years of age in the DAPT (Dual Antiplatelet Therapy) Study, a randomized trial comparing 30 versus 12 months of DAPT following percutaneous coronary intervention, had data linked to Medicare claims (n=1326), and a previously validated claims-based index was used to define frailty. Net adverse clinical events, a composite of all-cause mortality, myocardial infarction, stroke, and major bleeding, were compared between frail and nonfrail patients. Patients defined as frail using claims data (12.0% of the cohort) had higher incidence of net adverse clinical events (23.1%) compared with nonfrail patients (10.7%; P<0.001) at 18-month follow-up and increased risk after multivariable adjustment (adjusted hazard ratio [HR], 2.24 [95% CI, 1.38-3.63]). There were no differences in effects of extended duration DAPT on net adverse clinical events for frail (HR, 1.42 [95% CI, 0.73-2.75]) and nonfrail patients (HR, 1.18 [95% CI, 0.83-1.68]; interaction P=0.61), although analyses were underpowered. Bleeding was highest among frail patients who received extended duration DAPT. Conclusions Among older patients in the DAPT Study, claims-defined frailty was associated with higher net adverse clinical events. Effects of extended duration DAPT were not different for frail patients, although comparisons were underpowered. Further investigation of how frailty influences ischemic and bleeding risks with DAPT are warranted. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00977938.

OCT utilization: Summary statistics from the LightLab clinical initiative

OBJECTIVES

The study describes the evolution of optical coherence tomography (OCT) adoption and performance during percutaneous coronary intervention (PCI) following implementation of a standardized LightLab (LL) workflow.

BACKGROUND

The purpose of the LL Clinical Initiative was to evaluate the impact of a standardized workflow on physician efficiency, decision making, and image quality.

METHODS

The LL Clinical Initiative is a multicenter, prospective, observational clinical program. Data were collected from 48 physicians at 17 U.S. centers from 01/21/19 to 06/08/21. The study included 401 OCT-guided PCIs during the baseline phase and 1898 during the LL workflow phases. The baseline phase consisted of physicians utilizing OCT at their discretion. After completing the baseline phase, the workflow progressed through multiple phases culminating in the expansion phase, which focused on addressing greater procedural complexity. The LL workflow utilized OCT to assess plaque Morphology, lesion Length, and vessel Diameter before PCI, and optimized results by treating Medial edge dissection, stent mal-Apposition, and stent under-eXpansion (MLD MAX). High-level summary statistics were generated to elucidate trends.

RESULTS

After program implementation, there was a rise in the number of PCIs where the LL workflow was utilized compared to the baseline phase (68% during the expansion phase vs. 41% at baseline; p for trend <0.0001). Adoption of the LL workflow was associated with progressively greater procedural and lesion complexity when OCT was performed pre- and post-PCI (87% vs. 52%, p < 0.0001; 55% vs. 37%, p < 0.0001, respectively). In addition, the quality of OCT imaging obtained improved after LL workflow introduction, with over 95% of pre- and post-PCI pullback quality considered usable during the expansion phase. Finally, there was a reduction in time spent on OCT interpretation, both pre-PCI (4.6 min vs. 7.5 min, p < 0.0001) and post-PCI (2.9 min vs. 5.3 min, p < 0.0001).

CONCLUSIONS

After completion of the standardized OCT-guided workflow, there was greater uptake of OCT imaging, incorporation in more complex procedures, procedural efficiency, and image quality.

Predicting Residual Angina After Chronic Total Occlusion Percutaneous Coronary Intervention: Insights from the OPEN‐CTO Registry

Background

Given that percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) is indicated primarily for symptom relief, identifying patients most likely to benefit is critically important for patient selection and shared decision‐making. Therefore, we identified factors associated with residual angina frequency after CTO PCI and developed a model to predict postprocedure anginal burden.

Methods and Results

Among patients in the OPEN‐CTO (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion Hybrid Procedures) registry, we evaluated the association between patient characteristics and residual angina frequency at 6 months, as assessed by the Seattle Angina Questionnaire Angina Frequency Scale. We then constructed a prediction model for angina status after CTO PCI using ordinal regression. Among 901 patients undergoing CTO PCI, 28% had no angina, 31% had monthly angina, 30% had weekly angina, and 12% had daily angina at baseline. Six months later, 53% of patients had a ≥20‐point increase in Seattle Angina Questionnaire Angina Frequency Scale score. The final model to predict residual angina after CTO PCI included baseline angina frequency, baseline nitroglycerin use frequency, dyspnea symptoms, depressive symptoms, number of antianginal medications, PCI indication, and presence of multiple CTO lesions and had a C index of 0.78. Baseline angina frequency and nitroglycerin use frequency explained 71% of the predictive power of the model, and the relationship between model components and angina improvement at 6 months varied by baseline angina status.

Conclusions

A 7‐component OPEN‐AP (OPEN‐CTO Angina Prediction) score can predict angina improvement and residual angina after CTO PCI using variables commonly available before intervention. These findings have implications for appropriate patient selection and counseling for CTO PCI.

Estimation of DAPT Study Treatment Effects in Contemporary Clinical Practice: Findings From the EXTEND-DAPT Study

BACKGROUND

Differences in patient characteristics, changes in treatment algorithms, and advances in medical technology could each influence the applicability of older randomized trial results to contemporary clinical practice. The DAPT Study (Dual Antiplatelet Therapy) found that longer-duration DAPT decreased ischemic events at the expense of greater bleeding, but subsequent evolution in stent technology and clinical practice may attenuate the benefit of prolonged DAPT in a contemporary population. We evaluated whether the DAPT Study population is different from a contemporary population of US patients receiving percutaneous coronary intervention and estimated the treatment effect of extended-duration antiplatelet therapy after percutaneous coronary intervention in this more contemporary cohort.

METHODS

We compared the characteristics of drug-eluting stent-treated patients randomly assigned in the DAPT Study to a sample of more contemporary drug-eluting stent-treated patients in the National Cardiovascular Data Registry CathPCI Registry from July 2016 to June 2017. After linking trial and registry data, we used inverse-odds of trial participation weighting to account for patient and procedural characteristics and estimated a contemporary real-world treatment effect of 30 versus 12 months of DAPT after coronary stent procedures.

RESULTS

The US drug-eluting stent-treated trial cohort included 8864 DAPT Study patients, and the registry cohort included 568 540 patients. Compared with the trial population, registry patients had more comorbidities and were more likely to present with myocardial infarction and receive 2nd-generation drug-eluting stents. After reweighting trial results to represent the registry population, there was no longer a significant effect of prolonged DAPT on reducing stent thrombosis (reweighted treatment effect: -0.40 [95% CI, -0.99% to 0.15%]), major adverse cardiac and cerebrovascular events (reweighted treatment effect, -0.52 [95% CI, -2.62% to 1.03%]), or myocardial infarction (reweighted treatment effect, -0.97% [95% CI, -2.75% to 0.18%]), but the increase in bleeding with prolonged DAPT persisted (reweighted treatment effect, 2.42% [95% CI, 0.79% to 3.91%]).

CONCLUSIONS

The differences between the patients and devices used in contemporary clinical practice compared with the DAPT Study were associated with the attenuation of benefits and greater harms attributable to prolonged DAPT duration. These findings limit the applicability of the average treatment effects from the DAPT Study in modern clinical practice.

Distal Radial Access in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the PROGRESS-CTO Registry

BACKGROUND

The outcomes of distal radial access (dRA) in chronic total occlusion percutaneous coronary intervention (CTO-PCI) have received limited study.

METHODS

We compared the clinical, angiographic, and procedural characteristics of 120 CTO-PCIs performed via dRA access with 2625 CTO-PCIs performed via proximal radial access (pRA) in a large, multicenter registry.

RESULTS

The dRA group had lower mean PROGRESS-CTO score than the pRA group (1.0 ± 1 vs 1.2 ± 1, respectively; P=.05), while J-CTO score (2.4 ± 1.2 vs 2.3 ± 1.3; P=.43) and PROGRESS-CTO Complications score (2.8 ± 1.8 vs 2.6 ± 1.9; P=.16) were similar in the dRA vs pRA groups, respectively. Technical success was similar in the 2 groups (90% dRA vs 86% pRA; P=.14). Concomitant use of femoral access did not alter procedural success. The incidence of major periprocedural adverse cardiac events was similar in the 2 groups (0.8% dRA vs 2.4% pRA; P=.26), whereas the incidence of tamponade requiring pericardiocentesis was lower with dRA (0% dRA vs 4.69% pRA; P<.001), as was air kerma radiation dose (median, 1.7 Gy; interquartile range [IQR], 0.97-2.63 Gy in the dRA group vs median, 2.27 Gy; IQR, 1.2-3.9 Gy in the pRA group; P<.001).

CONCLUSIONS

Use of dRA in CTO-PCI is associated with similar procedural success and risk of complications as compared with pRA.

Long-term outcomes of percutaneous coronary intervention for in-stent restenosis among Medicare beneficiaries

BACKGROUND

In-stent restenosis (ISR) is highly prevalent and leads to repeat revascularisation. Long-term implications of ISR are poorly understood.

AIMS

This study aimed to evaluate the long-term outcomes of patients undergoing percutaneous coronary intervention (PCI) for ISR.

METHODS

National Cardiovascular Data Registry CathPCI records for individuals aged ≥65 years undergoing PCI from July 2009 to December 2014 were linked to Medicare claims. Baseline characteristics and long-term rates of death, myocardial infarction (MI), repeat revascularisation including target vessel revascularisation (TVR), and major adverse cardiovascular and cerebrovascular events (MACCE) were compared between ISR PCI versus de novo lesion PCI.

RESULTS

Of 653,304 individuals, 10.2% underwent ISR PCI and 89.8% underwent de novo lesion PCI. The median duration of follow-up was 825 days (quartile 1: 352 days-quartile 3: 1,379 days). The frequency of MACCE (55.6% vs 45.0%; p<0.001), all-cause mortality (27.8% vs 25.5%; p<0.001), MI (19.0% vs 12.3%; p<0.001), repeat revascularisation (31.9% vs 18.6%; p<0.001), TVR (22.4% vs 8.0%; p<0.001), and stroke (8.8% vs 8.3%; p=0.005) was higher after ISR PCI. After multivariable adjustment, ISR PCI remained associated with worse long-term outcomes than after de novo lesion PCI (hazard ratio [HR] for MACCE 1.24 [95% CI: 1.22, 1.26], mortality 1.07 [95% CI: 1.05, 1.09], MI 1.44 [95% CI: 1.40, 1.48], repeat revascularisation 1.55 [95% CI: 1.51, 1.59], and TVR 2.50 [95% CI: 2.42, 2.58]).

CONCLUSIONS

ISR PCI was common and was associated with a significantly higher risk of recurrent long-term major ischaemic events compared to patients undergoing de novo lesion PCI. There remains a need for new strategies to minimise ISR.

Comparability of Event Adjudication Versus Administrative Billing Claims for Outcome Ascertainment in the DAPT Study: Findings From the EXTEND-DAPT Study

BACKGROUND

Data from administrative claims may provide an efficient alternative for end point ascertainment in clinical trials. However, it is uncertain how well claims data compare to adjudication by a clinical events committee in trials of patients with cardiovascular disease.

METHODS

We matched 1336 patients ≥65 years old who received percutaneous coronary intervention in the DAPT (Dual Antiplatelet Therapy) Study with the National Cardiovascular Data Registry CathPCI Registry linked to Medicare claims as part of the EXTEND (Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data) Study. Adjudicated trial end points were compared with Medicare claims data with International Classification of Diseases, Ninth Revision codes from inpatient hospitalizations using time-to-event analyses, sensitivity, specificity, positive predictive value, negative predictive value, and kappa statistics.

RESULTS

At 21-month follow-up, the cumulative incidence of major adverse cardiovascular and cerebrovascular events (combined mortality, myocardial infarction, and stroke) was similar between trial-adjudicated events and claims data (7.9% versus 7.2%, respectively; P=0.50). Bleeding rates were lower using adjudicated events compared with claims (5.0% versus 8.6%, respectively; P<0.001). The sensitivity and positive predictive value of comprehensive billing codes for identifying adjudicated events were 65.6% and 85.7% for myocardial infarction, 61.5% and 47.1% for stroke, and 76.8% and 39.3% for bleeding, respectively. Specificity and negative predictive value for all outcomes ranged from 93.7% to 99.5%. All 39 adjudicated deaths were identified using Medicare data. Kappa statistics assessing agreement between events for myocardial infarction, stroke, and bleeding were 0.73, 0.52, and 0.49, respectively.

CONCLUSIONS

Claims data had moderate agreement with adjudication for myocardial infarction and poor agreement but high specificity for bleeding and stroke in the DAPT Study. Deaths were identified equivalently. Using claims data in clinical trials could be an efficient way to assess mortality among Medicare patients and may help detect other outcomes, although additional monitoring is likely needed to ensure accurate assessment of events.

Impact of adherence to the hybrid algorithm for initial crossing strategy selection in chronic total occlusion percutaneous coronary intervention

INTRODUCTION AND OBJECTIVES

The hybrid algorithm was designed to assist with initial and subsequent crossing strategy selection in chronic total occlusion (CTO) percutaneous coronary interventions (PCIs). However, the success of the initially selected strategy has received limited study.

METHODS

We examined the impact of adherence to the hybrid algorithm recommendation for initial CTO crossing technique selection in 4178 CTO PCIs from a large multicenter registry.

RESULTS

The initial crossing strategy was concordant with the hybrid algorithm recommendation in 1833 interventions (44%). Patients in the concordant group had a similar age to those in the discordant group but a lower mean J-CTO score (2.0 ± 1.4 vs 2.8 ± 1.1; P < .01). The concordant group showed higher technical success with the first crossing strategy (68% vs 48%; P < .01) and higher overall technical success (88% vs 83%; P < .01) with no difference in the incidence of in-hospital major adverse events (1.8% vs 2.3%; P = .26). In multivariable analysis, after adjustment for age, prior myocardial infarction, prior PCI, prior coronary artery bypass grafting, J-CTO score, and scheduled CTO PCI, nonadherence to the hybrid algorithm was independently associated with lower technical success of the initial crossing strategy (odds ratio, 0.55; 95% confidence interval, 0.48-0.64; P < .01).

CONCLUSIONS

Adherence to the hybrid algorithm for initial crossing strategy selection is associated with higher CTO PCI success but similar in-hospital major adverse cardiac events.

Follow-up Outcomes After Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With and Without Prior Coronary Artery Bypass Graft Surgery: Insights From the PROGRESS-CTO Registry

BACKGROUND

Long-term outcomes of patients with prior coronary artery bypass graft (CABG) surgery undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study.

METHODS

We compared the clinical and angiographic characteristics and procedural and follow-up outcomes of patients with and without prior CABG in a multicenter international registry.

RESULTS

Of the 1572 patients included in this analysis, a total of 498 (32%) had prior CABG. Prior CABG patients had higher J-CTO scores (2.9 ± 1.1 vs 2.2 ± 1.3; P<.001) and were less likely to undergo PCI of the left anterior descending artery (16.7% vs 29.6%; P<.001). The retrograde technique was used more often (47.4% vs 28.2%; P<.001) and was successful more often (27.4% vs 17.1%; P<.001) in the prior CABG group vs the non-prior CABG group. Technical success was lower in prior CABG patients (82.6% vs 87.9%; P<.01) with similar incidence of in-hospital major adverse cardiovascular events (3.4% vs 3%; P=.65), although in-hospital mortality was higher in the prior CABG group (2.4% vs 1.0%; P=.04). At 1-year follow-up, the composite endpoint of death, myocardial infarction, and revascularization was higher in prior CABG patients (21.79% vs 12.73%; hazard ratio, 1.76; 95% confidence interval, 1.27-2.45; P<.001).

CONCLUSION

Compared with non-prior CABG patients, prior CABG patients undergoing CTO-PCI had lower technical success and higher incidence of acute and follow-up adverse cardiovascular events.

Use of Administrative Claims to Assess Outcomes and Treatment Effect in Randomized Clinical Trials for Transcatheter Aortic Valve Replacement: Findings From the EXTEND Study

BACKGROUND

Whether passively collected data can substitute for adjudicated outcomes to reproduce the magnitude and direction of treatment effect observed in cardiovascular clinical trials is not well known.

METHODS

We linked adults ≥65 years of age in the HiR (US CoreValve Pivotal High Risk) and SURTAVI trials (Surgical or Transcatheter Aortic Valve Replacement in Intermediate-Risk Patients) to 100% Medicare inpatient claims, January 1, 2011, to December 31, 2016. Primary (eg, death and stroke) and secondary trial end points were compared across treatment arms (eg, transcatheter aortic valve replacement [TAVR] versus surgical aortic valve replacement [SAVR]) using trial-adjudicated outcomes versus outcomes derived from claims at 1 year (HiR) or 2 years (SURTAVI).

RESULTS

Among 600 linked HiR participants (linkage rate, 80.0%), the rate of the trial's primary end point of all-cause mortality occurred in 13.7% of patients receiving TAVR and 16.4% of patients receiving SAVR at 1 year by using both trial data (hazard ratio, 0.84 [95% CI, 0.65-1.09]; P=0.33) and claims data (hazard ratio, 0.86 [95% CI, 0.66-1.11]; P=0.34; interaction P value=0.80). Noninferiority of TAVR relative to SAVR was seen by using both trial- and claims-based outcomes (P_{noninferiority}<0.001 for both). Among 1005 linked SURTAVI trial participants (linkage rate, 60.5%), the trial's primary end point was 12.9% for TAVR and 13.1% for SAVR using trial data (hazard ratio, 1.08 [95% CI, 0.79-1.48]; P=0.90), and 11.3% for TAVR and 12.5% for SAVR patients using claims data (hazard ratio, 1.02 [95% CI, 0.73-1.41]; P=0.58; interaction P value=0.89). TAVR was noninferior to SAVR when compared using both trial and claims (P_{noninferiority}<0.001 for both). Rates of procedural secondary outcomes (eg, aortic valve reintervention, pacemaker rates) were more closely concordant between trial and claims data than nonprocedural outcomes (eg, stroke, bleeding, cardiogenic shock).

CONCLUSIONS

In the HiR and SURTAVI trials, ascertainment of trial primary end points using claims reproduced both the magnitude and direction of treatment effect in comparison with adjudicated event data, but nonfatal and nonprocedural secondary outcomes were not as well reproduced. Use of claims to substitute for adjudicated outcomes in traditional trial treatment comparisons may be valid and feasible for all-cause mortality and certain procedural outcomes but may be less suitable for other end points.

Abstract 20: Use of Administrative Claims to Ascertain Outcomes in Randomized Clinical Trials for Transcatheter Aortic Valve Replacement: Findings From the Extending Trial-based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study

Introduction: Administrative claims may be a low cost alternative to traditional clinical trial event adjudication, but whether claims data can validly substitute for adjudicated outcomes to reproduce trial-derived treatment effects is uncertain.

Methods: We linked adults aged ≥65 in the US CoreValve Pivotal High Risk (HiR) and Surgical or Transcatheter Aortic Valve Replacement in Intermediate-Risk Patients (SURTAVI) Trials to 100% Medicare inpatient claims (2003-2016). Primary (i.e. death and stroke) and secondary trial endpoints (i.e. bleeding, acute kidney injury, cardiogenic shock, pacemaker implantation, aortic valve reintervention, myocardial infarction, and major adverse cerebrovascular and cardiovascular events [MACCE]) were compared across treatment arms (i.e. TAVR vs. SAVR) using outcomes derived from claims at 1 year (HiR) or 2 years (SURTAVI), and compared with trial-adjudicated outcomes.

Results: Among 600 linked HiR participants (linkage rate 80.0%), the rate of the trial’s primary endpoint of all-cause mortality at 1-year was 13.7% for TAVR and 16.4% for SAVR using both trial data (HR 0.84, 95% CI 0.65-1.09; p = 0.33) and claims data (HR 0.86, 95% CI 0.66-1.11; p = 0.34; interaction p-value = 0.80) ( Figure ). Among 1004 linked SURTAVI trial participants (linkage rate 60.5%), the trial’s primary endpoint of combined death and stroke at 2-years was 12.9% for TAVR and 13.1% for SAVR using trial data (HR 1.08, 95% CI 0.79-1.48, p = 0.90), and 11.3% for TAVR and 12.5% for SAVR patients using claims data (HR 1.02, 95% CI 0.73-1.41, p = 0.58; interaction p-value = 0.89) ( Figure ). Procedural secondary outcomes (e.g., aortic valve reintervention, pacemaker implantation) were more concordant between trials and claims than non-procedural outcomes (e.g. bleeding, cardiogenic shock, stroke). Acute kidney injury, myocardial infarction, and MACCE outcomes were also concordant between data types.

Conclusions: In both HiR and SURTAVI trials, ascertainment of trial primary endpoints using claims reproduced both the magnitude and direction of treatment effect observed in adjudicated event data. Non-fatal secondary outcomes displayed variable concordance. Use of claims to substitute for adjudicated outcomes in traditional trial treatment comparisons may be a valid alternative for some endpoints.

Contemporary Use and Trends in Unprotected Left Main Coronary Artery Percutaneous Coronary Intervention in the United States: An Analysis of the National Cardiovascular Data Registry Research to Practice Initiative

Importance

Recent data support percutaneous revascularization as an alternative to coronary artery bypass grafting in unprotected left main (ULM) coronary lesions. However, the relevance of these trials to current practice is unclear, as patterns and outcomes of ULM percutaneous coronary intervention (PCI) in contemporary US clinical practice are not well studied.

Objective

To define the current practice of ULM PCI and its outcomes and compare these with findings reported in clinical trials.

Design, Setting, and Participants

This cross-sectional multicenter analysis included data collected from 1662 institutions participating in the National Cardiovascular Data Registry (NCDR) CathPCI Registry between April 2009 and July 2016. Data were collected from 33 128 patients undergoing ULM PCI and 3 309 034 patients undergoing all other PCI. Data were analyzed from June 2017 to May 2018.

Main Outcomes and Measures

Patient and procedural characteristics and their temporal trends were compared between ULM PCI and all other PCI. In-hospital major adverse clinical events (ie, death, myocardial infarction, stroke, and emergent coronary artery bypass grafting) were compared using hierarchical logistic regression. Characteristics and outcomes were also compared against clinical trial cohorts.

Results

Of the 3 342 162 included patients, 2 223 570 (66.5%) were male, and the mean (SD) age was 64.2 (12.1) years. Unprotected left main PCI represented 1.0% (33 128 of 3 342 162) of all procedures, modestly increasing from 0.7% to 1.3% over time. The mean (SD) annualized ULM PCI volume was 0.5 (1.5) procedures for operators and 3.2 (6.1) procedures for facilities, with only 1808 of 10 971 operators (16.5%) and 892 of 1662 facilities (53.7%) performing an average of 1 or more ULM PCI annually. After adjustment, major adverse clinical events occurred more frequently with ULM PCI compared with all other PCI (odds ratio, 1.46; 95% CI, 1.39-1.53). Compared with clinical trial populations, patients in the CathPCI Registry were older with more comorbid conditions, and adverse events were more frequent.

Conclusions and Relevance

Use of ULM PCI has increased over time, but overall use remains low. These findings suggest that ULM PCI occurs infrequently in the United States and in an older and more comorbid population than that seen in clinical trials.

Association of Physician Variation in Use of Manual Aspiration Thrombectomy With Outcomes Following Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction: The National Cardiovascular Data Registry CathPCI Registry

Importance

Following negative randomized clinical trials, US guidelines downgraded support for routine manual aspiration thrombectomy (AT) during primary percutaneous coronary intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI). However, some PCI operators continue to endorse a clinical benefit with AT use despite the lack of supportive data.

Objective

To examine temporal trends and comparative outcomes of AT use during pPCI for STEMI.

Design, Setting, and Participants

Retrospective cohort study of the National Cardiovascular Data Registry (NCDR) CathPCI Registry from July 1, 2009, to June 30, 2016, to assess temporal trends and in-hospital outcomes associated with AT use. To evaluate outcomes through 180 days, a subanalysis was conducted among Centers for Medicare and Medicaid Services-linked patients from July 1, 2009, through December 31, 2014. The comparative effectiveness analysis was performed using instrumental variable analyses to account for treatment selection bias. The instrumental variable was operator's preference to use AT during pPCI. Data were analyzed between February 1, 2017, and April 1, 2018.

Exposures

Aspiration thrombectomy use during pPCI for STEMI.

Main Outcomes and Measures

Primary outcomes included in-hospital stroke and death. Secondary outcomes included heart failure, stroke, all-cause rehospitalization, and death through 180 days of follow-up.

Results

Among all pPCIs performed (683 584), the mean (SD) age of patients was 61.7 (12.8) years, 489 257 were male (71.6%), and 596 384 were white (87.2%). Among patients undergoing pPCI, AT use increased from 2009 through 2011, with peak use of 13.8%. This was followed by a decline of more than 9%, reaching 4.7% by mid-2016. Overall, AT was used in 10.8% of pPCIs (lowest operator group median, 0%; highest operator group median, 33.8%). After instrumental variable analysis, AT use was associated with no difference in in-hospital death (adjusted absolute risk difference, -0.18%; 95% CI, -0.53% to 0.16%; P = .29) and a small increase in in-hospital stroke (adjusted RD, 0.14%; 95% CI, 0.01%-0.30%; P = .03). Among Centers for Medicare and Medicaid Services-linked patients, AT use was not associated with differences in death, heart failure, stroke, or rehospitalization at 180 days.

Conclusions and Relevance

In this large, nationwide analysis, AT use during STEMI pPCI declined by more than 50% since 2011, with use as of mid-2016 at less than 5%. Selective AT use was associated with a small excess risk of in-hospital stroke and no difference in other outcomes through 180 days of follow-up.

The Impact of Peripheral Artery Disease in Chronic Total Occlusion Percutaneous Coronary Intervention (Insights From PROGRESS-CTO Registry)

The impact of peripheral artery disease (PAD) in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We reviewed 3999 CTO PCIs performed in 3914 patients between 2012 and 2018 at 25 centers, 14% of whom had a history of PAD. We compared the clinical and angiographic characteristics and procedural outcomes of patients with versus without history of PAD. Patients with PAD were older (67 ± 9 vs 64 ± 10 years, P < .001) and had a higher prevalence of cardiovascular risk factors. They also had more complex lesions as illustrated by higher Japanese CTO score (2.7 ± 1.2 vs 2.4 ± 1.3, P < .001). In patients with PAD, the final crossing technique was less often antegrade wire escalation (40% vs 51%, P < .001) and more often the retrograde approach (23 vs 20%, P < .001) and antegrade dissection/reentry (20% vs 16%, P < .001). Technical success was similar between the 2 study groups (84% vs 87%, P = .127), but procedural success was lower for patients with PAD (81% vs 85%, P = .015). The incidence of in-hospital major adverse cardiac events was higher among patients with PAD (3% vs 2%, P = .046). In conclusion, patients with PAD undergoing CTO PCI have more comorbidities, more complex lesions, and lower procedural success.

Comparison of Clinical Trials and Administrative Claims to Identify Stroke Among Patients Undergoing Aortic Valve Replacement: Findings From the EXTEND Study

BACKGROUND

Cerebrovascular events (CVEs) are devastating complications after aortic valve replacement. We assessed whether billing claims accurately identify CVEs in place of clinical event adjudication in structural heart disease trials.

METHODS

Adult participants in the US CoreValve High Risk and SURTAVI trials (Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients) were linked to Medicare inpatient claims from January 1, 2006 to December 31, 2016. Claims consistent with CVEs within 14 days of a similar trial-adjudicated CVE were considered a match. The sensitivity, specificity, and positive and negative predictive values of International Classification of Diseases, Ninth and Tenth Revisions, Clinical Modification billing codes for cerebrovascular disease were determined against trial-defined CVEs as the criterion standard. Kaplan-Meier estimates of claims-defined versus trial-defined CVEs were compared.

RESULTS

Among 4230 linked trial participants (linkage rate 79.8%), 550 (13.0%) sustained 630 adjudicated CVEs over a 5-year follow-up period. Linked and nonlinked individuals were similar. An algorithm using 4 International Classification of Diseases, Ninth Revision, Clinical Modification codes (434.91, 434.11, 433.11, and 997.02) had a sensitivity of 60.9%, specificity of 99.0%, positive predictive value of 86.5%, and negative predictive value of 95.8% for identifying a trial-adjudicated ischemic stroke. An algorithm using 3 International Classification of Diseases, Tenth Revision, Clinical Modification codes (I63.9, I63.40, I63.49) had a sensitivity of 66.7%, specificity of 99.4%, positive predictive value of 88.9%, and negative predictive value of 97.6%.

CONCLUSIONS

In linked clinical trial and Medicare claims data, 4 International Classification of Diseases, Ninth Revision, Clinical Modification and 3 International Classification of Diseases, Tenth Revision, Clinical Modification billing codes identified half of trial-adjudicated CVEs during follow-up with high specificity and predictive value, but imperfect sensitivity. Although low sensitivity may limit the use of claims to substitute for traditional trial outcomes to identify CVEs, high specificity suggests claims could be used to trigger evaluation of neurological events, potentially improving the efficiency of the evaluation of techniques and devices designed to reduce such events.

Left Main Chronic Total Occlusion Percutaneous Coronary Intervention: A Case Series

BACKGROUND

Left main coronary artery (LMCA) chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

METHODS

We reviewed 4436 CTO-PCIs performed in 4340 patients between 2012 and 2018 at 25 sites. LMCA-CTO-PCI was performed in 20 cases (0.45%). We examined the clinical and angiographic characteristics and procedural outcomes of these cases.

RESULTS

Mean patient age was 68 ± 11 years and 65% were men. Most patients (85%) had undergone prior coronary artery bypass graft surgery and had a protected left main. Mean J-CTO score was 2.7 ± 1.3, mean PROGRESS-CTO score was 1.3 ± 1.1, and mean PROGRESS-CTO Complications score was 3.8 ± 1.9. Antegrade-wire escalation was the most common successful crossing strategy (50%), followed by retrograde crossing (30%) and antegrade dissection/re-entry (10%). Technical and procedural success rates were both 85%. One patient with failed LMCA-CTO-PCI had periprocedural myocardial infarction. Median procedure time was 178 minutes (interquartile range [IQR], 123-250 minutes), median contrast volume was 190 mL (IQR, 133-339 mL), and patient air kerma radiation dose was 2.6 Gray (IQR, 1.3-3.9 Gray).

CONCLUSIONS

LMCA-CTO-PCI is infrequent, is performed mostly in patients with prior coronary artery bypass graft surgery, and is associated with good procedural outcomes.

Effect of Short Procedural Duration With Bivalirudin on Increased Risk of Acute Stent Thrombosis in Patients With STEMI: A Secondary Analysis of the HORIZONS-AMI Randomized Clinical Trial

Importance

Bivalirudin has been associated with reduced bleeding and mortality during primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI). However, increased rates of acute stent thrombosis (AST) have been noted when bivalirudin is discontinued at the end of the procedure, which is perhaps related to this medication's short half-life.

Objectives

To evaluate the clinical effect of procedure duration on AST when either bivalirudin or heparin plus glycoprotein IIb/IIIa receptor inhibitor (GPI) is used.

Design, Setting, and Participants

An ad hoc analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) clinical trial was performed between March 1, 2015, and April 30, 2016, on patients who underwent primary percutaneous coronary intervention with stents and were randomized 1:1 to bivalirudin or heparin plus GPI. Defined as the difference between the patient's arrival at the catheterization laboratory and the patient's final angiogram. Participants included 3602 patients with STEMI, aged 18 years or older, who were undergoing primary percutaneous coronary intervention and presenting less than 12 hours from symptom onset.

Main Outcomes and Measures

Clinical events committee-adjudicated definite AST (occurring ≤24 hours after percutaneous coronary intervention).

Results

Among patients included in this analysis, procedure time was identified in 1286 receiving bivalirudin and 1412 receiving heparin plus GPI. Shorter procedures were defined as the lowest quartile of duration (<45 minutes). Patients undergoing shorter procedures were younger and less likely to be hypertensive and smokers. Shorter procedures were less complicated with fewer stents implanted, less multivessel stenting, less thrombus, and less no-reflow. An increased risk of definite AST was associated with shorter than with longer procedures with bivalirudin (7 [2.1%] vs 7 [0.7%]; relative risk, 2.87; 95% CI, 1.01-8.17; P = .04) but not with heparin plus GPI (0 vs 3 [0.3%]; P = .30).

Conclusions and Relevance

Despite less procedural complexity, shorter primary percutaneous coronary intervention time was associated with an increased risk of AST in patients treated with bivalirudin but not patients treated with heparin plus GPI, possibly because of the rapid offset of bivalirudin's antithrombotic effect during a window of limited oral antiplatelet action.

Trial Registration

clinicaltrials.gov Identifier: NCT00433966.

Validating the use of registries and claims data to support randomized trials: Rationale and design of the Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study

BACKGROUND

Randomized controlled trials are the "gold standard" for comparing the safety and efficacy of therapies but may be limited due to high costs, lack of feasibility, and difficulty enrolling "real-world" patient populations. The Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study seeks to evaluate whether data collected within procedural registries and claims databases can reproduce trial results by substituting surrogate non-trial-based variables for exposures and outcomes.

METHODS AND RESULTS

Patient-level data from 2 clinical trial programs-the Dual Antiplatelet Therapy Study and the United States CoreValve Studies-will be linked to a combination of national registry, administrative claims, and health system data. The concordance between baseline and outcomes data collected within nontrial data sets and trial information, including adjudicated end point events, will be assessed. We will compare the study results obtained using these alternative data sources to those derived using trial-ascertained variables and end points using trial-adjudicated end points and covariates.

CONCLUSIONS

Linkage of trials to registries and claims data represents an opportunity to use alternative data sources in place of and as adjuncts to randomized clinical trial data but requires further validation. The results of this research will help determine how these data sources can be used to improve our present and future understanding of new medical treatments.

Cost implications of intraprocedural thrombotic events and bleeding in percutaneous coronary intervention: Results from the CHAMPION PHOENIX ECONOMICS Study

BACKGROUND

Despite improvements in percutaneous coronary intervention (PCI), intraprocedural thrombotic events (IPTE) and bleeding complications occur and are prognostically important. These have not been included in prior economic studies.

METHODS

PHOENIX ECONOMICS was a substudy of the CHAMPION PHOENIX trial, evaluating cangrelor during PCI. Hospital bills were reviewed from 1,171 patients enrolled at 22 of 63 US sites. Costs were estimated using standard methods including resource-based accounting, hospital billing data, and the Medicare fee schedule. Bleeding and IPTE, defined as abrupt vessel closure (transient or sustained), new/suspected thrombus, new clot on wire/catheter, no reflow, side-branch occlusion, procedural stent thrombosis or urgent need for CABG were identified. Costs were calculated according to whether a complication occurred and type of event. Multivariate analyses were used to estimate the incremental costs of IPTE and postprocedural events.

RESULTS

IPTE occurred in 4.3% and were associated with higher catheterization laboratory and overall index hospitalization costs by $2,734 (95%CI $1,117, $4,351; P = 0.001) and $6,354 (95% CI $4,122, $8,586; P < 0.001), respectively. IPTE were associated with MI (35.4% vs. 3.6%; P < 0.001), out-of-laboratory stent thrombosis (4.2% vs. 0.1%; 0 = 0.005), ischemia driven revascularization (12.5% vs. 0.3%; P < 0.001), but not mortality (2.1% vs. 0.2%; P = 0.12) vs. no procedural thrombotic complication. By comparison, ACUITY minor bleeding increased hospitalization cost by $1,416 (95%CI = 312, $2,519; P = 0.012). ACUITY major bleeding increased cost of hospitalization by $7,894 (95%CI $4,154, $11,635; P < 0.001).

CONCLUSIONS

IPTE and bleeding complications, though infrequent, are associated with substantial increased cost. These complications should be collected in economic assessments of PCI.

Novel Method for Exchange of Impella Circulatory Assist Catheter: The "Trojan Horse" Technique

Patients with an indwelling Impella may require escalation of hemodynamic support or exchange to another circulatory assistance platform. As such, preservation of vascular access is preferable in cases where anticoagulation cannot be discontinued or to facilitate exchange to an alternative catheter or closure device. Challenges exist in avoiding bleeding and loss of wire access in these situations. We describe a single-access "Trojan Horse" technique that minimizes bleeding while maintaining arterial access for rapid exchange of this percutaneous ventricular assist device.

Serum phospholipid fraction of polyunsaturated fatty acids is the preferred indicator for nutrition and health status in hemodialysis patients

Long chain (LC) polyunsaturated fatty acids (PUFA) are major components of cell membrane phospholipids (PL) and serve as precursors for numerous bioactive lipid derivatives. Fatty acids (FA) are routinely analyzed in biological samples to assess composition of tissues, cells, and lipid fractions. In human studies, serum or plasma is often used because of their easy procurement. However, the lipid pool in serum and plasma is a mixture of triacylglycerol (TG), PL, cholesterol and its esters, and other components. Herein, we report findings from a serum FA analysis after fractionation of polar and neutral lipids by solid phase extraction in a large cohort of 400 hemodialysis patients. LC PUFA were found concentrated in the polar fraction compared to the total or the neutral lipid fraction. When correlated with clinical markers of disease, a greater number of significant correlations were found for PUFA in polar compared to total or the neutral fraction. We also observed that polar lipids are a reliable reflection of LC PUFA status compared to the total or neutral fractions because the latter are diluted by non-essential FA. The relative amounts of LC PUFA in the total and neutral fractions reflect the contribution of TG in blood that varies with diet, age, and physiologic state. Our data indicate that LC PUFA in the polar fraction are superior indicators of bioactive FA-status than in the total or the neutral fraction and should be used to establish important links between PUFA status, their bioactive substrates in hemodialysis patients.

Type 4a myocardial infarction: Incidence, risk factors, and long-term outcomes

OBJECTIVES

To assess the incidence of and outcomes related to periprocedural (Type 4a) myocardial infarction (MI) in a cohort of patients undergoing percutaneous coronary intervention (PCI) for stable coronary disease or non ST-elevation acute coronary syndrome with stable or falling cardiac troponin levels.

BACKGROUND

The 2012 Third Universal Definition for Type 4a MI has not been prospectively studied in routine clinical practice.

METHODS

The study included 516 patients undergoing eligible PCI at a single institution. Data were extracted from the National Cardiovascular Data Registry, review of electronic medical records, and telephone interviews. Clinical outcomes assessed at one year included all-cause mortality, recurrent MI, or any repeat coronary revascularization.

RESULTS

Based on the Third Universal Definition of MI, 53 (10.3%) patients met criteria for Type 4a MI and 116 (22.5%) had myocardial injury. The Type 4a MI and myocardial injury groups each had significantly higher numbers of stents, longer stent lengths, and more use of rotational atherectomy than the control group. Type 4a MI was not associated with one-year mortality. The composite endpoint of death or recurrent MI at one year was similar between the Type 4a MI and myocardial injury groups (12 vs. 11%; P > 0.05), which were both higher compared with the control group (3%; P = 0.02, 0.03).

CONCLUSIONS

Type 4a MI and myocardial injury were frequent, and were associated with more complicated index PCI and more frequent death or recurrent MI at one year as compared with the control group. © 2016 Wiley Periodicals, Inc.

Removal of Soluble Fms-Like Tyrosine Kinase-1 by Dextran Sulfate Apheresis in Preeclampsia

Preeclampsia is a devastating complication of pregnancy. Soluble Fms-like tyrosine kinase-1 (sFlt-1) is an antiangiogenic protein believed to mediate the signs and symptoms of preeclampsia. We conducted an open pilot study to evaluate the safety and potential efficacy of therapeutic apheresis with a plasma-specific dextran sulfate column to remove circulating sFlt-1 in 11 pregnant women (20-38 years of age) with very preterm preeclampsia (23-32 weeks of gestation, systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg, new onset protein/creatinine ratio >0.30 g/g, and sFlt-1/placental growth factor ratio >85). We evaluated the extent of sFlt-1 removal, proteinuria reduction, pregnancy continuation, and neonatal and fetal safety of apheresis after one (n=6), two (n=4), or three (n=1) apheresis treatments. Mean sFlt-1 levels were reduced by 18% (range 7%-28%) with concomitant reductions of 44% in protein/creatinine ratios. Pregnancy continued for 8 days (range 2-11) and 15 days (range 11-21) in women treated once and multiple times, respectively, compared with 3 days (range 0-14) in untreated contemporaneous preeclampsia controls (n=22). Transient maternal BP reduction during apheresis was managed by withholding pre-apheresis antihypertensive therapy, saline prehydration, and reducing blood flow through the apheresis column. Compared with infants born prematurely to untreated women with and without preeclampsia (n=22 per group), no adverse effects of apheresis were observed. In conclusion, therapeutic apheresis reduced circulating sFlt-1 and proteinuria in women with very preterm preeclampsia and appeared to prolong pregnancy without major adverse maternal or fetal consequences. A controlled trial is warranted to confirm these findings.

Nutritional vitamin D supplementation in dialysis: a randomized trial

BACKGROUND AND OBJECTIVES

Vitamin D (25-hydroxyvitamin D; 25[OH]D) deficiency is common in patients initiating long-term hemodialysis, but the safety and efficacy of nutritional vitamin D supplementation in this population remain uncertain.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This randomized, placebo-controlled, parallel-group multicenter trial compared two doses of ergocalciferol with placebo between October 2009 and March 2013. Hemodialysis patients (n=105) with 25(OH)D levels ≤32 ng/ml from 32 centers in the Northeast United States were randomly assigned to oral ergocalciferol, 50,000 IU weekly (n=36) or monthly (n=33), or placebo (n=36) for a 12-week treatment period. The primary endpoint was the achievement of vitamin D sufficiency (25[OH]D >32 ng/ml) at the end of the 12-week treatment period. Survival was assessed through 1 year.

RESULTS

Baseline characteristics were similar across all arms, with overall mean±SD 25(OH)D levels of 21.9±6.9 ng/ml. At 12 weeks, vitamin D sufficiency (25[OH]D >32 ng/ml) was achieved in 91% (weekly), 66% (monthly), and 35% (placebo) (P<0.001). Mean 25(OH)D was significantly higher in both the weekly (49.8±2.3 ng/ml; P<0.001) and monthly (38.3±2.4 ng/ml; P=0.001) arms compared with placebo (27.4±2.3 ng/ml). Calcium, phosphate, parathyroid hormone levels, and active vitamin D treatment did not differ between groups. All-cause and cause-specific hospitalizations and adverse events were similar between groups during the intervention period. Lower all-cause mortality among ergocalciferol-treated participants was not statistically significant (hazard ratio, 0.28; 95% confidence interval, 0.07 to 1.19).

CONCLUSIONS

Oral ergocalciferol can increase 25(OH)D levels in incident hemodialysis patients without significant alterations in blood calcium, phosphate, or parathyroid hormone during a 12-week period.

Vitamin D and chronic kidney disease-mineral bone disease (CKD-MBD)

Chronic kidney disease (CKD) is a modern day epidemic and has significant morbidity and mortality implications. Mineral and bone disorders are common in CKD and are now collectively referred to as CKD- mineral and bone disorder (MBD). These abnormalities begin to appear even in early stages of CKD and contribute to the pathogenesis of renal osteodystrophy. Alteration in vitamin D metabolism is one of the key features of CKD-MBD that has major clinical and research implications. This review focuses on biology, epidemiology and management aspects of these alterations in vitamin D metabolism as they relate to skeletal aspects of CKD-MBD in adult humans.

Vitamin D-binding protein and vitamin D status of black Americans and white Americans

BACKGROUND

Low levels of total 25-hydroxyvitamin D are common among black Americans. Vitamin D-binding protein has not been considered in the assessment of vitamin D deficiency.

METHODS

In the Healthy Aging in Neighborhoods of Diversity across the Life Span cohort of blacks and whites (2085 participants), we measured levels of total 25-hydroxyvitamin D, vitamin D-binding protein, and parathyroid hormone as well as bone mineral density (BMD). We genotyped study participants for two common polymorphisms in the vitamin D-binding protein gene (rs7041 and rs4588). We estimated levels of bioavailable 25-hydroxyvitamin D in homozygous participants.

RESULTS

Mean (±SE) levels of both total 25-hydroxyvitamin D and vitamin D-binding protein were lower in blacks than in whites (total 25-hydroxyvitamin D, 15.6±0.2 ng per milliliter vs. 25.8±0.4 ng per milliliter, P<0.001; vitamin D-binding protein, 168±3 μg per milliliter vs. 337±5 μg per milliliter, P<0.001). Genetic polymorphisms independently appeared to explain 79.4% and 9.9% of the variation in levels of vitamin D-binding protein and total 25-hydroxyvitamin D, respectively. BMD was higher in blacks than in whites (1.05±0.01 g per square centimeter vs. 0.94±0.01 g per square centimeter, P<0.001). Levels of parathyroid hormone increased with decreasing levels of total or bioavailable 25-hydroxyvitamin D (P<0.001 for both relationships), yet within each quintile of parathyroid hormone concentration, blacks had significantly lower levels of total 25-hydroxyvitamin D than whites. Among homozygous participants, blacks and whites had similar levels of bioavailable 25-hydroxyvitamin D overall (2.9±0.1 ng per milliliter and 3.1±0.1 ng per milliliter, respectively; P=0.71) and within quintiles of parathyroid hormone concentration.

CONCLUSIONS

Community-dwelling black Americans, as compared with whites, had low levels of total 25-hydroxyvitamin D and vitamin D-binding protein, resulting in similar concentrations of estimated bioavailable 25-hydroxyvitamin D. Racial differences in the prevalence of common genetic polymorphisms provide a likely explanation for this observation. (Funded by the National Institute on Aging and others.).

Carbamylation of serum albumin and erythropoietin resistance in end stage kidney disease

BACKGROUND AND OBJECTIVES

The mechanisms underlying erythropoietin resistance are not fully understood. Carbamylation is a post-translational protein modification that can alter the function of proteins, such as erythropoietin. The hypothesis of this study is that carbamylation burden is independently associated with erythropoietin resistance.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a nonconcurrent prospective cohort study of incident hemodialysis patients in the United States, carbamylated albumin, a surrogate of overall carbamylation burden, in 158 individuals at day 90 of dialysis initiation and erythropoietin resistance index (defined as average weekly erythropoietin dose [U] per kg body weight per hemoglobin [g/dl]) over the subsequent 90 days were measured. Linear regression was used to describe the relationship between carbamylated albumin and erythropoietin resistance index. Logistic regression characterized the relationship between erythropoietin resistance index, 1-year mortality, and carbamylation.

RESULTS

The median percent carbamylated albumin was 0.77% (interquartile range=0.58%-0.93%). Median erythropoietin resistance index was 18.7 units/kg per gram per deciliter (interquartile range=8.1-35.6 units/kg per gram per deciliter). Multivariable adjusted analysis showed that the highest quartile of carbamylated albumin was associated with a 72% higher erythropoietin resistance index compared with the lowest carbamylation quartile (P=0.01). Increasing erythropoietin resistance index was associated with a higher risk of death (odds ratio per unit increase in log-erythropoietin resistance index, 1.69; 95% confidence interval, 1.06 to 2.70). However, the association between erythropoietin resistance index and mortality was no longer statistically significant when carbamylation was included in the analysis (odds ratio, 1.44; 95% confidence interval, 0.87 to 2.37), with carbamylation showing the dominant association with death (odds ratio for high versus low carbamylation quartile, 4.53; 95% confidence interval, 1.20 to 17.10).

CONCLUSION

Carbamylation was associated with higher erythropoietin resistance index in incident dialysis patients and a better predictor of mortality than erythropoietin resistance index.

Active vitamin D treatment for reduction of residual proteinuria: a systematic review

Despite renin-angiotensin-aldosterone system blockade, which retards progression of CKD by reducing proteinuria, many patients with CKD have residual proteinuria, an independent risk factor for disease progression. We aimed to address whether active vitamin D analogs reduce residual proteinuria. We systematically searched for trials published between 1950 and September of 2012 in the Medline, Embase, and Cochrane Library databases. All randomized controlled trials of vitamin D analogs in patients with CKD that reported an effect on proteinuria with sample size≥50 were selected. Mean differences of proteinuria change over time and odds ratios for reaching ≥15% proteinuria decrease from baseline to last measurement were synthesized under a random effects model. From 907 citations retrieved, six studies (four studies with paricalcitol and two studies with calcitriol) providing data for 688 patients were included in the meta-analysis. Most patients (84%) used an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker throughout the study. Active vitamin D analogs reduced proteinuria (weighted mean difference from baseline to last measurement was -16% [95% CI, -13% to -18%]) compared with controls (+6% [95% CI, 0% to +12%]; P<0.001). Proteinuria reduction was achieved more commonly in patients treated with an active vitamin D analog (204/390 patients) than control patients (86/298 patients; OR, 2.72 [95% CI, 1.82 to 4.07]; P<0.001). Thus, active vitamin D analogs may further reduce proteinuria in CKD patients in addition to current regimens. Future studies should address whether vitamin D therapy also retards progressive renal functional decline.

Fatty acids and other risk factors for sudden cardiac death in patients starting hemodialysis

BACKGROUND

Little is known about risk factors for sudden cardiac death in hemodialysis patients during the high-risk first year of dialysis. We therefore undertook to identify such risk factors in a nationally representative cohort and were able to include baseline levels of blood fatty acids, some of which influence arrhythmogenicity and sudden cardiac death risk.

DESIGN

The study cohort included 100 patients who died of sudden cardiac death during the first year of hemodialysis and 300 frequency-matched controls. Using the elastic net statistical method, numerous demographic and clinical characteristics were included with baseline total serum levels for 11 major fatty acids (model 1) and with serum phospholipid fractions of these same fatty acids (model 2). Final models included only covariates that had a non-zero coefficient.

RESULTS

In model 1, serum albumin [odds ratio (95% CI): 0.55 (0.33-0.93); p = 0.03] and total serum long-chain n-3 docosapentaenoic acid [0.70 (0.51-0.97); p = 0.03] were inversely associated with the odds of sudden cardiac death, while the total serum saturated fatty acid level had a direct association [1.01 (1.00-1.02); p = 0.03]. In model 2, serum albumin and docosapentaenoic acid remained inversely associated with sudden cardiac death in a similar manner as in model 1. Pulse pressure also had an inverse association [0.96 (0.93-1.00); p < 0.05].

CONCLUSIONS

Several factors, including blood content of docosapentaenoic acid and saturated fatty acids, were associated with the odds of sudden cardiac death during year one of hemodialysis. These results raise the possibility that dietary modification may reduce sudden death risk.

Vitamin D reduces left atrial volume in patients with left ventricular hypertrophy and chronic kidney disease

BACKGROUND

Left atrial enlargement, a sensitive integrator of left ventricular diastolic function, is associated with increased cardiovascular morbidity and mortality. Vitamin D is linked to lower cardiovascular morbidity, possibly modifying cardiac structure and function; however, firm evidence is lacking. We assessed the effect of an activated vitamin D analog on left atrial volume index (LAVi) in a post hoc analysis of the PRIMO trial (clinicaltrials.gov: NCT00497146).

METHODS AND RESULTS

One hundred ninety-six patients with chronic kidney disease (estimated glomerular filtration rate 15-60 mL/min per 1.73 m(2)), mild to moderate left ventricular hypertrophy, and preserved ejection fraction were randomly assigned to 2 μg of oral paricalcitol or matching placebo for 48 weeks. Two-dimensional echocardiography was obtained at baseline and at 24 and 48 weeks after initiation of therapy. Over the study period, there was a significant decrease in LAVi (-2.79 mL/m(2), 95% CI -4.00 to -1.59 mL/m(2)) in the paricalcitol group compared with the placebo group (-0.70 mL/m(2) [95% CI -1.93 to 0.53 mL/m(2)], P = .002). Paricalcitol also attenuated the rise in levels of brain natriuretic peptide (10.8% in paricalcitol vs 21.3% in placebo, P = .02). For the entire population, the change in brain natriuretic peptide correlated with change in LAVi (r = 0.17, P = .03).

CONCLUSIONS

Forty-eight weeks of therapy with an active vitamin D analog reduces LAVi and attenuates the rise of BNP. In a population where only few therapies alter cardiovascular related morbidity and mortality, these post hoc results warrant further confirmation.

Low blood levels of long-chain n-3 polyunsaturated fatty acids in US hemodialysis patients: clinical implications

BACKGROUND

Cardioprotective and other clinical benefits of long-chain n-3 polyunsaturated fatty acids (PUFA) are inversely related to dietary intake and hence blood content. We therefore investigated, in the first study of its kind, the blood content and distribution of these fatty acids in a large representative population of US hemodialysis patients.

METHODS

Frozen sera were obtained from 400 individuals who were part of a large, contemporary, representative cohort of US incident hemodialysis patients. Long-chain n-3 PUFA were measured in total serum lipids and in the neutral and polar serum fractions using gas chromatography and solid phase extraction techniques. Mean long-chain n-3 PUFA levels were compared to levels in other dialysis and nondialysis populations from published reports.

RESULTS

The study population was qualitatively similar to the overall US hemodialysis population in terms of major clinical characteristics. Long-chain n-3 PUFA were present in the serum polar fraction, with essentially none being detected in the neutral fraction (p < 0.0001 for polar vs. neutral fractions for all three long-chain n-3 PUFA). Mean serum long-chain n-3 PUFA levels (weight percent (±SD): total 1.55 ± 0.95, polar 3.99 ± 1.45) were low compared to nondialysis and most other non-US hemodialysis cohorts.

CONCLUSIONS

While US hemodialysis patients have a blood distribution of long-chain n-3 PUFA that is similar to that in the general population, blood content is among the lowest recorded in the medical literature. This has implications for renal dietary recommendations and makes US patients an ideal group for testing the clinical effects of long-chain n-3 PUFA supplementation.

Vitamin D therapy and cardiac structure and function in patients with chronic kidney disease: the PRIMO randomized controlled trial

CONTEXT

Vitamin D is associated with decreased cardiovascular-related morbidity and mortality, possibly by modifying cardiac structure and function, yet firm evidence for either remains lacking.

OBJECTIVE

To determine the effects of an active vitamin D compound, paricalcitol, on left ventricular mass over 48 weeks in patients with an estimated glomerular filtration rate of 15 to 60 mL/min/1.73 m(2).

DESIGN, SETTING, AND PARTICIPANTS

Multinational, double-blind, randomized placebo-controlled trial among 227 patients with chronic kidney disease, mild to moderate left ventricular hypertrophy, and preserved left ventricular ejection fraction, conducted in 11 countries from July 2008 through September 2010.

INTERVENTION

Participants were randomly assigned to receive oral paricalcitol, 2 μg/d (n =115), or matching placebo (n = 112).

MAIN OUTCOME MEASURES

Change in left ventricular mass index over 48 weeks by cardiovascular magnetic resonance imaging. Secondary end points included echocardiographic changes in left ventricular diastolic function.

RESULTS

Treatment with paricalcitol reduced parathyroid hormone levels within 4 weeks and maintained levels within the normal range throughout the study duration. At 48 weeks, the change in left ventricular mass index did not differ between treatment groups (paricalcitol group, 0.34 g/m(2.7) [95% CI, -0.14 to 0.83 g/m(2.7)] vs placebo group, -0.07 g/m(2.7) [95% CI, -0.55 to 0.42 g/m(2.7)]). Doppler measures of diastolic function including peak early diastolic lateral mitral annular tissue velocity (paricalcitol group, -0.01 cm/s [95% CI, -0.63 to 0.60 cm/s] vs placebo group, -0.30 cm/s [95% CI, -0.93 to 0.34 cm/s]) also did not differ. Episodes of hypercalcemia were more frequent in the paricalcitol group compared with the placebo group.

CONCLUSION

Forty-eight week therapy with paricalcitol did not alter left ventricular mass index or improve certain measures of diastolic dysfunction in patients with chronic kidney disease.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00497146.

Soluble erythropoietin receptor contributes to erythropoietin resistance in end-stage renal disease

BACKGROUND

Erythropoietin is a growth factor commonly used to manage anemia in patients with chronic kidney disease. A significant clinical challenge is relative resistance to erythropoietin, which leads to use of successively higher erythropoietin doses, failure to achieve target hemoglobin levels, and increased risk of adverse outcomes. Erythropoietin acts through the erythropoietin receptor (EpoR) present in erythroblasts. Alternative mRNA splicing produces a soluble form of EpoR (sEpoR) found in human blood, however its role in anemia is not known.

METHODS AND FINDINGS

Using archived serum samples obtained from subjects with end stage kidney disease we show that sEpoR is detectable as a 27kDa protein in the serum of dialysis patients, and that higher serum sEpoR levels correlate with increased erythropoietin requirements. Soluble EpoR inhibits erythropoietin mediated signal transducer and activator of transcription 5 (Stat5) phosphorylation in cell lines expressing EpoR. Importantly, we demonstrate that serum from patients with elevated sEpoR levels blocks this phosphorylation in ex vivo studies. Finally, we show that sEpoR is increased in the supernatant of a human erythroleukaemia cell line when stimulated by inflammatory mediators such as interleukin-6 and tumor necrosis factor alpha implying a link between inflammation and erythropoietin resistance.

CONCLUSIONS

These observations suggest that sEpoR levels may contribute to erythropoietin resistance in end stage renal disease, and that sEpoR production may be mediated by pro-inflammatory cytokines.