iFR Can Assess Need For Coronary Revascularization Without Adenosine

MedicalResearch.com Interview with:

Dr. Justin Davies PhD Senior Reserch Fellow and Hononary Consultant Cardiologist National Heart and Lung Institute, Imperial College Londo

Dr. Davies

Dr. Justin Davies PhD
Senior Reserch Fellow and Hononary Consultant Cardiologist
National Heart and Lung Institute,
Imperial College London

MedicalResearch.com: What is the background for this study?

Response: We know from the FAME study that compared to angiography alone, FFR guided revascularization improves long-term clinical outcomes for our patients. Despite this, adoption of FFR into everyday clinical practice remains stubbornly low. One major factor for this is the need for adenosine (or other potent vasodilator medications) in order to perform an FFR measurement. Adenosine is expensive, unpleasant for the patient, time consuming and even potentially harmful.

iFR is a newer coronary physiology index that does not require adenosine for its measurement. In the prospective, multi center, blinded DEFINE FLAIR study, 2492 patients were randomly assigned to either FFR guided revascularisation or iFR guided revascularization and followed up for a period of 1 year.
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Instantaneous Wave-free Ratio vs Fractional Flow Reserve to Guide PCI

MedicalResearch.com Interview with:

Dr. Matthias Götberg MD PhD Department of Cardiology, Clinical Sciences Lund University, Skåne University Hospital Lund, Sweden

Dr. Matthias Götberg

Dr. Matthias Götberg MD PhD
Department of Cardiology, Clinical Sciences
Lund University, Skåne University Hospital
Lund, Sweden

MedicalResearch.com: What is the background for this study?

Response: Cardiologists encounter patients with narrowing of the coronary arteries on a daily basis. They typically use visual estimation of the severity of narrowing when performing coronary angiography, but it is difficult to accurately assess, based on a visual estimation alone, whether a stent is needed to widen the artery and allow the blood to more freely.

FFR (Fractional Flow Reserve) is more precise tool and results in better outcomes than using angiography alone to assess narrowing of the coronary arteries. With FFR, the doctor threads a thin wire through the coronary artery and measures the loss of blood pressure across the narrowed area. To acquire an accurate measurement, the patient must be given adenosine, which is a drug that dilates the blood vessels during the procedure. This drug causes discomfort; patients describe having difficulty breathing or feeling as if someone is sitting on their chest. The drug also adds to the cost of the procedure and can have other rare but serious side effects.

iFR (Instantaneous Wave-Free Ratio) is also based on coronary blood pressure measurements using a thin wire, but unlike FFR, it uses a mathematical algorithm to measure the pressure in the coronary artery only when the heart is relaxed and the coronary blood flow is high. As a result, a vasodilator drug is not needed.

iFR has been validated in smaller trials and have been found to be equally good as FFR to detect ischemia, but larger randomized outcome trials are lacking.

iFR-Swedeheart is a Scandinavian Registry-based Randomized Clinical Trial (RRCT) in which 2000 patients were randomized between iFR and FFR as strategies for performing assessment of narrowed coronary vessels. The primary composite endpoint at 12 months was all-cause death, non-fatal myocardial infarction, and unplanned revascularization.

RRCT is a new trial design originating from Scandinavia using existing web-based national quality registries for online data entry, randomization and tracking of events. This allows for a very high inclusion rate and low costs to run clinical trials while ensuring robust data quality.  Continue reading

SPECT MPI to Predict Heart Attacks: Stress Agents Regadenoson vs Adenosine

Dr. Afshin Farzaneh-Far, M.D. University of Illinois at ChicagoMedicalResearch.com Interview with:
Dr. Afshin Farzaneh-Far, M.D.

University of Illinois at Chicago

MedicalResearch.com: What are the main findings of the study?

Answer: Traditionally SPECT MPI has been performed with adenosine which has a
significant body of published prognostic data.

Regadenoson is a selective A2A receptor agonist and is now the stress
agent most widely used in the United States. Unlike adenosine, regadenoson
is given as a bolus rather than as an infusion, simplifying the testing
protocol and is better-tolerated.

However, despite increasing use of regadenoson, there is very limited data
on risk prediction using this agent.

This study showed that the ability of SPECT MPI to predict heart attacks
and death is the same for the new stress agent Regadenoson as it is for
the old agent Adenosine.

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