IMAGE-HF Project I-C: Computed Tomographic Coronary Angiography for Heart Failure Patients

Hypotheses Primary Hypothesis: Compared to ICA, a diagnostic strategy algorithm using CTA for patients with HF of unknown etiology or where the definition of coronary anatomy is required for diagnosis and management, will result in a reduction in downstream resource utilization and per patient cost.

Secondary Hypotheses: I) Compared to standard care, a strategy that uses CTA will achieve: a) similar composite clinical events (CCE), quality of life (QoL), major adverse cardiac events (MACE); b) a lower rate of procedure related complications (death, MI, stroke, vascular complications, severe allergic reactions; contrast nephropathy); c) a lower rate of normal ICA. II) Using patient-based analysis and vessel-based analysis, CTA has very good agreement with ICA among patients with HF in the CTA arm who proceed to ICA.

Objectives The primary objective is to understand the role of CTA in patients with HF of unknown etiology. We propose a prospective randomized study of 250 patients to examine the potential impact of CTA compared to ICAon resource utilization and health care costs in patients with HF with unknown CAD status.

Secondary objectives are to: compare CCE, QoL and MACE in the CTA and ICA arms. Radiation exposure and safety in both groups will also be assessed.

Trial design The proposed trial is a multicentre randomized controlled trial of 250 patients. In addition, a retrospective review of the current CTA and ICA databases at the University of Ottawa Heart Institute will be conducted to identify an additional cohort of patients (200-400) where the imaging modality decision has already been made. These patients are not eligible for randomization, but will be entered into a registry.

Trial interventions - Randomization All HF patients requiring investigation to determine the etiology of HF (ischemic versus non-ischemic) will be screened for the study. Patients will be randomized to the investigation arm CTA or ICA. Patients will be stratified according to recruitment site and pre-test probability for obstructive CAD. A stratified block (varying sizes) randomization scheme will be used. Within each strata, patients will be randomized with varying block sizes into the two study groups. A central randomization scheme (envelope), which will ensure concealment, will be used and the local research co-ordinator will perform patient assignments. The randomization scheme will be generated by a statistician using a SAS macro.

Inclusion criteria

Eligible HF patients with an admission to hospital or emergency room for heart failure

OR

a documented history of left ventricular dysfunction (LVEF <50%)

OR

a documented history of Class ll-lV heart failure symptoms, in the preceding 12 months prior to enrollment, in whom the diagnosis of CAD is uncertain or the definition of coronary anatomy is required for diagnosis and management.

Exclusion criteria

• Age < 18 years or lack of consent,
• Renal Insufficiency (GFR < 45 ml/min);
• Allergy to intravenous contrast agents;
• Contraindication to radiation exposure (e.g. pregnancy);
• Uncontrolled HR at time of scan (as per local clinical routine)
• History of revascularization (CABG or PCI);
• Atrial fibrillation, frequent atrial or ventricular ectopy (> 1 / minute);
• Unable to perform 20 second breath-hold;
• CTA or ICA within the preceding 12 months