Influence of Clinical Trial Site Enrollment on Patient Characteristics, Protocol Completion, and End Points: Insights From the ASCEND-HF Trial (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure).
Most international acute heart failure trials have failed to show benefit with respect to key end points. The impact of site enrollment and protocol execution on trial performance is unclear.



We assessed the impact of varying site enrollment volume among all 7141 acute heart failure patients from the ASCEND-HF trial (Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure). Overall, 398 sites enrolled ≥1 patient, and median enrollment was 12 patients (interquartile range, 5-23). Patients from high enrolling sites (>60 patients/site) tended to have lower ejection fraction, worse New York Heart Association functional class, and lower utilization of guideline-directed medical therapy but fewer comorbidities and lower B-type natriuretic peptide level. Every 10 patient increase (up to 100 patients) in site enrollment correlated with lower likelihood of protocol noncompletion (odds ratio, 0.93; 95% confidence interval [CI], 0.89-0.98). After adjustment, increasing site enrollment predicted higher risk of persistent dyspnea at 6 hours (per 10 patient increase: odds ratio 1.02; 95% CI, 1.01-1.03) but not at 24 hours (odds ratio, 0.99; 95% CI, 0.98-1.00). Higher site enrollment was independently associated with lower risk of 30-day death or rehospitalization (per 10 patient increase: odds ratio, 0.98, 95% CI, 0.96-0.99) but not 180-day mortality (hazard ratio, 0.99; 95% CI, 0.98-1.01). The influence of increasing site enrollment on clinical end points varied across geographic regions with strongest associations in Latin America and Asia-Pacific (all interaction P<0.01).



In this large, acute heart failure trial, site enrollment correlated with protocol completion and was independently associated with trial end points. Individual and regional site performance present challenges to be considered in design of future acute heart failure trials.



URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.). stephen.greene@duke.edu.
Stephen J
SJ
Greene
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Adrian F
AF
Hernandez
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Jie-Lena
JL
Sun
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Marco
M
Metra
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Javed
J
Butler
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Andrew P
AP
Ambrosy
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Justin A
JA
Ezekowitz
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Randall C
RC
Starling
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
John R
JR
Teerlink
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Phillip J
PJ
Schulte
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Adriaan A
AA
Voors
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Paul W
PW
Armstrong
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Christopher M
CM
O'Connor
From the Division of Cardiology, Duke University Medical Center, Durham, NC (S.J.G., A.F.H., A.P.A., C.M.O., R.J.M.); Duke Clinical Research Institute, Durham, NC (A.F.H., J.-L.S., A.P.A., P.J.S., C.M.O., R.J.M.); Cardiology, University of Brescia, Italy (M.M.); Division of Cardiology, Stony Brook University, NY (J.B.); Canadian VIGOUR Center, University of Alberta, Edmonton, Canada (J.A.E., P.W.A.); Cleveland Clinic, OH (R.C.S.); Section of Cardiology, San Francisco Veterans Affairs Medical Center, School of Medicine, University of California San Francisco (J.R.T.); and Department of Cardiology, University Medical Center Groningen, The Netherlands (A.A.V.).
Robert J
RJ
Mentz
D000368:Aged; D016009:Chi-Square Distribution; D018450:Disease Progression; D004417:Dyspnea / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control; D023381:Endpoint Determination; D005260:Female; D006333:Heart Failure / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D015999:Multivariate Analysis; D045283:Natriuretic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D020097:Natriuretic Peptide, Brain / Q000009:adverse effects / Q000627:therapeutic use*; D016017:Odds Ratio; D010352:Patient Dropouts; D010359:Patient Readmission; D018579:Patient Selection; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D020127:Recovery of Function; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
D045283:Natriuretic Agents; D020097:Natriuretic Peptide, Brain
clinical trial; heart failure; patient discharge; quality of life