Prevalence of QT interval prolongation in patients admitted to cardiac care units and frequency of subsequent administration of QT interval-prolonging drugs: A prospective, observational study in a large urban academic medical center in the US

James E. Tisdale, Heather A. Wroblewski, Brian R. Overholser, Joanna R. Kingery, Tate N. Trujillo, Richard Kovacs

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

Background: Cardiac arrest due to torsades de pointes (TdP) is a rare but catastrophic event in hospitals. Patients admitted to cardiac units are at higher risk of drug-induced QT interval prolongation and TdP, due to a preponderance of risk factors. Few data exist regarding the prevalence of QT interval prolongation in patients admitted to cardiac units or the frequency of administering QT interval-prolonging drugs to patients presenting with QT interval prolongation. Objective: The aim of this study was to determine the prevalence of Bazett'scorrected QT (QT c) interval prolongation upon admission to cardiac units and the proportion of patients presenting with QT c interval prolongation who are subsequently administered QT interval-prolonging drugs during hospitalization. Methods: This was a prospective, observational study conducted over a 1-year period (October 2008-October 2009) in 1159 consecutive patients admitted to two cardiac units in a large urban academic medical centre located in Indianapolis, IN, USA. Patients were enrolled into the study at the time of admission to the hospital and were followed daily during hospitalization. Exclusion criteria were age <18 years, ECG rhythm of complete ventricular pacing, and patient designation as 'outpatient' in a bed and/or duration of stay <24 hours. Data collected included demographic information, pas medical history, daily progress notes, medication administration records, laboratory data, ECGs, telemetry monitoring strips and diagnostic reports. All patients underwent continuous cardiac telemetry monitoring and/or had a baseline 12-lead ECG obtained within 4 hours of admission. QT intervals were determined manually from lead II of 12-lead ECGs or from continuous lead II telemetry monitoring strips. QT c interval prolongation was defined as ≥470 ms for males and ≥480 ms for females. In both males and females, QT c interval >500 ms was considered abnormally high. A medication was classified as QT interval-prolonging if there were published data indicating that the drug causes QT interval prolongation and/or TdP. Study endpoints were (i) prevalence of QT c interval prolongation upon admission to the Cardiac Medical Critical Care Unit (CMCCU) or an Advanced Heart Care Unit (AHCU); (ii) proportion of patients admitted to the CMCCU/AHCU with QT c interval prolongation who subsequently were administered QT intervalprolonging drugs during hospitalization; (iii) the proportion of these higher-risk patients in whom TdP risk factor monitoring was performed; (iv) proportion of patients with QT c interval prolongation who subsequently received QT prolonging drugs and who experienced further QT c interval prolongation. Results: Of 1159 patients enrolled, 259 patients met exclusion criteria, resulting in a final sample size of 900 patients. Patient characteristics: mean (± SD) age, 65 ± 15 years; female, 47%; Caucasian, 70%. Admitting diagnoses: heart failure (22%), myocardial infarction (16%), atrial fibrillation (9%), sudden cardiac arrest (3%). QT c interval prolongation was present in 27.9% of patients on admission; 18.2% had QT c interval >500 ms. Of 251 patients admitted with QT c interval prolongation, 87 (34.7%) were subsequently administered QT interval-prolonging drugs. Of 166 patients admitted with QTc interval >500 ms, 70 (42.2%) were subsequently administered QT intervalprolonging drugs; additional QT c interval prolongation ≥60 ms occurred in 57.1% of these patients. Conclusions: QT c interval prolongation is common among patients admitted to cardiac units. QT interval-prolonging drugs are commonly prescribed to patients presenting with QT c interval prolongation.

Original languageEnglish
Pages (from-to)459-470
Number of pages12
JournalDrug Safety
Volume35
Issue number6
DOIs
StatePublished - 2012

Fingerprint

Observational Studies
Prospective Studies
Pharmaceutical Preparations
Torsades de Pointes
Hospitalization
Critical Care
Monitoring
Patient Admission
Sudden Cardiac Death
Heart Arrest
Sample Size
Atrial Fibrillation

Keywords

  • Acute-heart-failure
  • Amiodarone
  • Angioplasty
  • Atrial-fibrillation
  • Azithromycin
  • Ciprofloxacin
  • Coronary-artery-disease
  • ECG
  • Erythromycin
  • Fluconazole
  • Heart-arrest
  • Levofloxacin
  • Methadone
  • Moxifloxacin
  • Myocardial-infarction
  • Procainamide
  • QT-interval-prolongation
  • Ranolazine
  • Sotalol
  • Torsades-de-pointes
  • Ziprasidone

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Pharmacology
  • Toxicology

Cite this

Prevalence of QT interval prolongation in patients admitted to cardiac care units and frequency of subsequent administration of QT interval-prolonging drugs : A prospective, observational study in a large urban academic medical center in the US. / Tisdale, James E.; Wroblewski, Heather A.; Overholser, Brian R.; Kingery, Joanna R.; Trujillo, Tate N.; Kovacs, Richard.

In: Drug Safety, Vol. 35, No. 6, 2012, p. 459-470.

Research output: Contribution to journalArticle

@article{a4f34ea004354fd09b088df70353ae9b,
title = "Prevalence of QT interval prolongation in patients admitted to cardiac care units and frequency of subsequent administration of QT interval-prolonging drugs: A prospective, observational study in a large urban academic medical center in the US",
abstract = "Background: Cardiac arrest due to torsades de pointes (TdP) is a rare but catastrophic event in hospitals. Patients admitted to cardiac units are at higher risk of drug-induced QT interval prolongation and TdP, due to a preponderance of risk factors. Few data exist regarding the prevalence of QT interval prolongation in patients admitted to cardiac units or the frequency of administering QT interval-prolonging drugs to patients presenting with QT interval prolongation. Objective: The aim of this study was to determine the prevalence of Bazett'scorrected QT (QT c) interval prolongation upon admission to cardiac units and the proportion of patients presenting with QT c interval prolongation who are subsequently administered QT interval-prolonging drugs during hospitalization. Methods: This was a prospective, observational study conducted over a 1-year period (October 2008-October 2009) in 1159 consecutive patients admitted to two cardiac units in a large urban academic medical centre located in Indianapolis, IN, USA. Patients were enrolled into the study at the time of admission to the hospital and were followed daily during hospitalization. Exclusion criteria were age <18 years, ECG rhythm of complete ventricular pacing, and patient designation as 'outpatient' in a bed and/or duration of stay <24 hours. Data collected included demographic information, pas medical history, daily progress notes, medication administration records, laboratory data, ECGs, telemetry monitoring strips and diagnostic reports. All patients underwent continuous cardiac telemetry monitoring and/or had a baseline 12-lead ECG obtained within 4 hours of admission. QT intervals were determined manually from lead II of 12-lead ECGs or from continuous lead II telemetry monitoring strips. QT c interval prolongation was defined as ≥470 ms for males and ≥480 ms for females. In both males and females, QT c interval >500 ms was considered abnormally high. A medication was classified as QT interval-prolonging if there were published data indicating that the drug causes QT interval prolongation and/or TdP. Study endpoints were (i) prevalence of QT c interval prolongation upon admission to the Cardiac Medical Critical Care Unit (CMCCU) or an Advanced Heart Care Unit (AHCU); (ii) proportion of patients admitted to the CMCCU/AHCU with QT c interval prolongation who subsequently were administered QT intervalprolonging drugs during hospitalization; (iii) the proportion of these higher-risk patients in whom TdP risk factor monitoring was performed; (iv) proportion of patients with QT c interval prolongation who subsequently received QT prolonging drugs and who experienced further QT c interval prolongation. Results: Of 1159 patients enrolled, 259 patients met exclusion criteria, resulting in a final sample size of 900 patients. Patient characteristics: mean (± SD) age, 65 ± 15 years; female, 47{\%}; Caucasian, 70{\%}. Admitting diagnoses: heart failure (22{\%}), myocardial infarction (16{\%}), atrial fibrillation (9{\%}), sudden cardiac arrest (3{\%}). QT c interval prolongation was present in 27.9{\%} of patients on admission; 18.2{\%} had QT c interval >500 ms. Of 251 patients admitted with QT c interval prolongation, 87 (34.7{\%}) were subsequently administered QT interval-prolonging drugs. Of 166 patients admitted with QTc interval >500 ms, 70 (42.2{\%}) were subsequently administered QT intervalprolonging drugs; additional QT c interval prolongation ≥60 ms occurred in 57.1{\%} of these patients. Conclusions: QT c interval prolongation is common among patients admitted to cardiac units. QT interval-prolonging drugs are commonly prescribed to patients presenting with QT c interval prolongation.",
keywords = "Acute-heart-failure, Amiodarone, Angioplasty, Atrial-fibrillation, Azithromycin, Ciprofloxacin, Coronary-artery-disease, ECG, Erythromycin, Fluconazole, Heart-arrest, Levofloxacin, Methadone, Moxifloxacin, Myocardial-infarction, Procainamide, QT-interval-prolongation, Ranolazine, Sotalol, Torsades-de-pointes, Ziprasidone",
author = "Tisdale, {James E.} and Wroblewski, {Heather A.} and Overholser, {Brian R.} and Kingery, {Joanna R.} and Trujillo, {Tate N.} and Richard Kovacs",
year = "2012",
doi = "10.2165/11598160-000000000-00000",
language = "English",
volume = "35",
pages = "459--470",
journal = "Drug Safety",
issn = "0114-5916",
publisher = "Adis International Ltd",
number = "6",

}

TY - JOUR

T1 - Prevalence of QT interval prolongation in patients admitted to cardiac care units and frequency of subsequent administration of QT interval-prolonging drugs

T2 - A prospective, observational study in a large urban academic medical center in the US

AU - Tisdale, James E.

AU - Wroblewski, Heather A.

AU - Overholser, Brian R.

AU - Kingery, Joanna R.

AU - Trujillo, Tate N.

AU - Kovacs, Richard

PY - 2012

Y1 - 2012

N2 - Background: Cardiac arrest due to torsades de pointes (TdP) is a rare but catastrophic event in hospitals. Patients admitted to cardiac units are at higher risk of drug-induced QT interval prolongation and TdP, due to a preponderance of risk factors. Few data exist regarding the prevalence of QT interval prolongation in patients admitted to cardiac units or the frequency of administering QT interval-prolonging drugs to patients presenting with QT interval prolongation. Objective: The aim of this study was to determine the prevalence of Bazett'scorrected QT (QT c) interval prolongation upon admission to cardiac units and the proportion of patients presenting with QT c interval prolongation who are subsequently administered QT interval-prolonging drugs during hospitalization. Methods: This was a prospective, observational study conducted over a 1-year period (October 2008-October 2009) in 1159 consecutive patients admitted to two cardiac units in a large urban academic medical centre located in Indianapolis, IN, USA. Patients were enrolled into the study at the time of admission to the hospital and were followed daily during hospitalization. Exclusion criteria were age <18 years, ECG rhythm of complete ventricular pacing, and patient designation as 'outpatient' in a bed and/or duration of stay <24 hours. Data collected included demographic information, pas medical history, daily progress notes, medication administration records, laboratory data, ECGs, telemetry monitoring strips and diagnostic reports. All patients underwent continuous cardiac telemetry monitoring and/or had a baseline 12-lead ECG obtained within 4 hours of admission. QT intervals were determined manually from lead II of 12-lead ECGs or from continuous lead II telemetry monitoring strips. QT c interval prolongation was defined as ≥470 ms for males and ≥480 ms for females. In both males and females, QT c interval >500 ms was considered abnormally high. A medication was classified as QT interval-prolonging if there were published data indicating that the drug causes QT interval prolongation and/or TdP. Study endpoints were (i) prevalence of QT c interval prolongation upon admission to the Cardiac Medical Critical Care Unit (CMCCU) or an Advanced Heart Care Unit (AHCU); (ii) proportion of patients admitted to the CMCCU/AHCU with QT c interval prolongation who subsequently were administered QT intervalprolonging drugs during hospitalization; (iii) the proportion of these higher-risk patients in whom TdP risk factor monitoring was performed; (iv) proportion of patients with QT c interval prolongation who subsequently received QT prolonging drugs and who experienced further QT c interval prolongation. Results: Of 1159 patients enrolled, 259 patients met exclusion criteria, resulting in a final sample size of 900 patients. Patient characteristics: mean (± SD) age, 65 ± 15 years; female, 47%; Caucasian, 70%. Admitting diagnoses: heart failure (22%), myocardial infarction (16%), atrial fibrillation (9%), sudden cardiac arrest (3%). QT c interval prolongation was present in 27.9% of patients on admission; 18.2% had QT c interval >500 ms. Of 251 patients admitted with QT c interval prolongation, 87 (34.7%) were subsequently administered QT interval-prolonging drugs. Of 166 patients admitted with QTc interval >500 ms, 70 (42.2%) were subsequently administered QT intervalprolonging drugs; additional QT c interval prolongation ≥60 ms occurred in 57.1% of these patients. Conclusions: QT c interval prolongation is common among patients admitted to cardiac units. QT interval-prolonging drugs are commonly prescribed to patients presenting with QT c interval prolongation.

AB - Background: Cardiac arrest due to torsades de pointes (TdP) is a rare but catastrophic event in hospitals. Patients admitted to cardiac units are at higher risk of drug-induced QT interval prolongation and TdP, due to a preponderance of risk factors. Few data exist regarding the prevalence of QT interval prolongation in patients admitted to cardiac units or the frequency of administering QT interval-prolonging drugs to patients presenting with QT interval prolongation. Objective: The aim of this study was to determine the prevalence of Bazett'scorrected QT (QT c) interval prolongation upon admission to cardiac units and the proportion of patients presenting with QT c interval prolongation who are subsequently administered QT interval-prolonging drugs during hospitalization. Methods: This was a prospective, observational study conducted over a 1-year period (October 2008-October 2009) in 1159 consecutive patients admitted to two cardiac units in a large urban academic medical centre located in Indianapolis, IN, USA. Patients were enrolled into the study at the time of admission to the hospital and were followed daily during hospitalization. Exclusion criteria were age <18 years, ECG rhythm of complete ventricular pacing, and patient designation as 'outpatient' in a bed and/or duration of stay <24 hours. Data collected included demographic information, pas medical history, daily progress notes, medication administration records, laboratory data, ECGs, telemetry monitoring strips and diagnostic reports. All patients underwent continuous cardiac telemetry monitoring and/or had a baseline 12-lead ECG obtained within 4 hours of admission. QT intervals were determined manually from lead II of 12-lead ECGs or from continuous lead II telemetry monitoring strips. QT c interval prolongation was defined as ≥470 ms for males and ≥480 ms for females. In both males and females, QT c interval >500 ms was considered abnormally high. A medication was classified as QT interval-prolonging if there were published data indicating that the drug causes QT interval prolongation and/or TdP. Study endpoints were (i) prevalence of QT c interval prolongation upon admission to the Cardiac Medical Critical Care Unit (CMCCU) or an Advanced Heart Care Unit (AHCU); (ii) proportion of patients admitted to the CMCCU/AHCU with QT c interval prolongation who subsequently were administered QT intervalprolonging drugs during hospitalization; (iii) the proportion of these higher-risk patients in whom TdP risk factor monitoring was performed; (iv) proportion of patients with QT c interval prolongation who subsequently received QT prolonging drugs and who experienced further QT c interval prolongation. Results: Of 1159 patients enrolled, 259 patients met exclusion criteria, resulting in a final sample size of 900 patients. Patient characteristics: mean (± SD) age, 65 ± 15 years; female, 47%; Caucasian, 70%. Admitting diagnoses: heart failure (22%), myocardial infarction (16%), atrial fibrillation (9%), sudden cardiac arrest (3%). QT c interval prolongation was present in 27.9% of patients on admission; 18.2% had QT c interval >500 ms. Of 251 patients admitted with QT c interval prolongation, 87 (34.7%) were subsequently administered QT interval-prolonging drugs. Of 166 patients admitted with QTc interval >500 ms, 70 (42.2%) were subsequently administered QT intervalprolonging drugs; additional QT c interval prolongation ≥60 ms occurred in 57.1% of these patients. Conclusions: QT c interval prolongation is common among patients admitted to cardiac units. QT interval-prolonging drugs are commonly prescribed to patients presenting with QT c interval prolongation.

KW - Acute-heart-failure

KW - Amiodarone

KW - Angioplasty

KW - Atrial-fibrillation

KW - Azithromycin

KW - Ciprofloxacin

KW - Coronary-artery-disease

KW - ECG

KW - Erythromycin

KW - Fluconazole

KW - Heart-arrest

KW - Levofloxacin

KW - Methadone

KW - Moxifloxacin

KW - Myocardial-infarction

KW - Procainamide

KW - QT-interval-prolongation

KW - Ranolazine

KW - Sotalol

KW - Torsades-de-pointes

KW - Ziprasidone

UR - http://www.scopus.com/inward/record.url?scp=84861376254&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84861376254&partnerID=8YFLogxK

U2 - 10.2165/11598160-000000000-00000

DO - 10.2165/11598160-000000000-00000

M3 - Article

C2 - 22612851

AN - SCOPUS:84861376254

VL - 35

SP - 459

EP - 470

JO - Drug Safety

JF - Drug Safety

SN - 0114-5916

IS - 6

ER -