Response to "Myocardial infarction in saphenous percutaneous intervention: Are we really doing our best?"
Article Outline
We would like to thank Lozano et al for their interest in our recent study.1 As pointed out by the author, percutaneous coronary intervention (PCI) in saphenous vein graft (SVG) remains cumbersome in contemporary practice. Its main limitations are distal embolization during the procedure and recurrent events related to disease progression. Because of these pitfalls, the prognosis of PCI in SVG is poor.2 To date, only a few techniques and devices are able to demonstrate improvement in the outcome and prognosis following PCI of SVG lesions. This is mainly attributed to the atherosclerotic nature of the disease in the SVG. Protection devices, both distal and proximal, were proposed to reduce the risk of distal embolization. Registries, however, have consistently observed that the usage rates for these devices is <30%.3 There are several reasons for this, including anatomic requirements, lack of a landing zone, malfunctioning due to improper sizing, complications, cost, and others. In addition, each device has a learning curve and because SVG PCI is not common in contemporary practice, operators may not feel competent to perform the procedure when needed. In fact, a recent article by Mehta et al3 observed that some centers do not use protective devices at all. Finally, these devices, although beneficial, were approved based on a reduction in major adverse cardiac events compared to conventional PCI because they decrease the rate of creatine phosphokinase elevation, which is a “soft” end point. No reduction in the death rate was observed in the American College of Cardiology–National Cardiovascular Data Registry. Overall, we agree with the author that a higher rate of protection device use may result in a reduction in intrahospital myocardial infarction (MI). In our experience, the rate of protection device use was similar to that of recent registry data (no MI vs MI: 28.7% vs 29.2%; P = .9). Although a significant difference in clinical outcome was observed in hospital between the 2 groups, this difference disappeared at 1 year (major adverse cardiac events: 7.2% vs 0.9%; P < .001 and 22.3% vs 19.1%; P = .4, respectively). The main finding of our study is that the new definition of procedural MI does not seem to carry a prognostic significance at 1 year and, thus, should not be used to evaluate new techniques or devices in SVG PCI. Further, the lack of significant difference between the 2 groups is related to the very poor long-term outcome of such intervention—with a mortality rate of 25% at 4 years. With accelerated disease progression in the SVG, it would be difficult to demonstrate the benefit of any device.3 Interestingly, Hong et al4 recently observed that negative remodeling and plaque growth were responsible for the rapid progression of atherosclerosis in SVG. Of importance is that low-density lipoprotein cholesterol correlated to long-term lumen loss. Thus, it seems that optimal medical therapy may be able to improve long-term results of SVG PCI.
References
- Prognostic value of procedure-related myocardial infarction according to the universal definition of myocardial infarction in saphenous vein graft interventions. Am Heart J. 2009;157:894–898
- Clinical correlates of long-term mortality after percutaneous interventions of saphenous vein grafts. Am Heart J. 2006;152:801–806
- Utilization of distal embolic protection in saphenous vein graft interventions (an analysis of 19,546 patients in the American College of Cardiology-National Cardiovascular Data Registry). Am J Cardiol. 2007;100:1114–1118
- Disease progression in nonintervened saphenous vein graft segments a serial intravascular ultrasound analysis. J Am Coll Cardiol. 2009;53:1257–1264
PII: S0002-8703(09)00475-X
doi:10.1016/j.ahj.2009.06.017
© 2009 Mosby, Inc. All rights reserved.
