CORRESPONDENCE: LETTER TO THE EDITOR
Fractional Flow Reserve–Guided Intervention of Angiographically Nonsignificant Coronary Stenoses
Umamahesh C. Rangasetty, MD* and
Charles Y. Lui, MD
* Division of Cardiology, University of Texas Medical Branch Galveston, 301 University Boulevard, Galveston, Texas 77555 (Email: cylui{at}utmb.edu).
We read with interest the recent DEFER (Deferral Versus Performance of PTCA in Patients Without Documented Ischemia) study by Pijls et al. (1) comparing results of percutaneous coronary intervention (PCI) with medical therapy in patients with stable coronary artery disease and angiographically intermediate stenotic lesions. The study demonstrated no beneficial effects of PCI in stenosis with fractional flow reserve (FFR) >0.75 (performance group) as compared with medical therapy (defer group) and increased major adverse cardiac events (MACE) in lesions with FFR <0.75 (reference group) during 5 years of follow-up.
It is interesting to note the high frequency of coronary artery bypass grafting (CABG) during 5 years of follow-up in the reference group (10.4%), especially given the fact that two-thirds of the patients had single-vessel disease, with normal left ventricular ejection fraction (68 ± 9), and few with diabetes (13%). This figure is definitely high as compared with that seen in concurrent studies such as COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) (2) and MASS II (Second Medicine, Angioplasty, or Surgery Study) (3), with the majority of their patients having multivessel coronary artery disease. Seventy-seven patients (6.7%) in the PCI arm of the COURAGE study underwent CABG after median 4.6 years, whereas MASS II reported 9.3% during 5 years of follow-up.
The DEFER study defined myocardial infarction using a 2-fold elevation of creatinine kinase, which is not a standard definition as reported by the joint committee of European Society of Cardiology/American College of Cardiology (4). Furthermore, the definition of acute myocardial infarction after PCI requires at least 3 times elevation above the upper limit of the normal (ULN) and another study reported 5 to 8 times the ULN (5). We believe that the definition used in the present study significantly increased the events of myocardial infarction both in hospital and during follow-up and might have led to increased MACE in the reference group (FFR <0.75).
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References
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- Pijls NH, Schaardenburgh PV, Manoharan G, et al. Percutaneous coronary intervention of functionally nonsignificant stenosis: 5-year follow-up of the DEFER study J Am Coll Cardiol 2007;49:2105-2111.[Abstract/Free Full Text]
- Boden WE, ORourke RA, Teo KK, et al. COURAGE Trial Research Group Optimal medical therapy with or without PCI for stable coronary disease N Engl J Med 2007;12:1503-1516.
- Hueb W, Lopes NH, Gersh BJ, et al. Five-year follow-up of the Medicine, Angioplasty, or Surgery Study (MASS II): a randomized controlled clinical trial of 3 therapeutic strategies for multivessel coronary artery disease Circulation 2007;6:1082-1089.
- The Joint European Society of Cardiology/American College of Cardiology Committee Myocardial infarction redefined—a consensus document of the Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction Eur Heart J 2000;21:1502-1513.[Abstract/Free Full Text]
- Levine GN, Kern MJ, Berger PB, et al. Management of patients undergoing percutaneous coronary revascularization Ann Intern Med 2003;139:123-136.[Abstract/Free Full Text]
Related articles in JACC:
- Reply
- Nico H.J. Pijls, Pepijn van Schaardenburg, Ganesh Manoharan, Erik Boersma, Jan-Willem Bech, Marcel vant Veer, Frits Bär, Jan Hoorntje, Jacques Koolen, William Wijns, and Bernard de Bruyne
JACC 2008 51: 1123-1124.
[Full Text]