Detection by Intracoronary Near-Infrared Spectroscopy of Lipid Core Plaque at Culprit Sites in Survivors of Cardiac Arrest

Abstract: With an estimated 300,000 cases occurring per year in the United States alone, sudden cardiac death remains a major public health problem and in many cases is the first manifestation of coronary artery disease. Autopsy studies have established that the causative event in many cases of sudden death is rupture of an intracoronary lipid core plaque with subsequent thrombus formation. Until recently, identification of lipid core plaque in vivo has not been possible; however, a combined near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) catheter has become available that can detect lipid core plaque in patients undergoing coronary angiography. In this report, we present findings in 5 patients who experienced a documented sudden cardiac arrest, were successfully resuscitated, and then were studied with intracoronary NIRS-IVUS to assess the extent and location of lipid core plaque. Although the detection of lipid core plaque at the culprit site in victims of sudden death is not novel, the novelty of the present report is that NIRS permitted identification of the large lipid core plaque underlying sudden cardiac arrest in vivo, a finding in striking accord with prior autopsy observations implicating ruptured lipid core plaque in the pathogenesis of sudden cardiac death.  

J INVASIVE CARDIOL 2014;26(2):78-79

Key words: near-infrared spectroscopy, lipid core plaque, sudden cardiac death

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With an estimated 300,000 cases occurring per year in the United States alone, sudden cardiac death remains a major public health problem and in many cases is the first manifestation of coronary artery disease.¹ Autopsy studies have established that the causative event in many cases of sudden death is rupture of an intracoronary lipid core plaque (LCP) with subsequent thrombus formation.² Until recently, identification of lipid core plaque in vivo has not been possible; however, a combined near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) catheter has become available that can detect lipid core plaque in patients undergoing coronary angiography.  

In this report, we present findings in 5 patients who experienced a documented sudden cardiac arrest, were successfully resuscitated, and were then studied with intracoronary NIRS-IVUS to assess the extent and location of lipid core plaque. Whereas in 1 case the cardiac arrest occurred in the emergency room while awaiting transfer to the catheterization laboratory, the other 4 cases were out-of-hospital cardiac arrests, including 2 cases that occurred prior to first medical contact. In all 5 cases, NIRS identified the presence of a large lipid core plaque in the culprit segment (Figure 1). 

Although the detection of lipid core plaque at the culprit site in victims of sudden death is not novel, the novelty of the present report is that NIRS permitted identification of the large lipid core plaque underlying sudden cardiac arrest in vivo, a finding in striking accord with prior autopsy observations implicating ruptured lipid core plaque in the pathogenesis of sudden cardiac death.² Consistent with prior in vivo studies linking lipid core plaque detected by NIRS to culprit lesions across the spectrum of acute coronary syndromes, including in ST-segment elevation myocardial infarction (STEMI), non-STEMI and unstable angina,^3,4 the present observations provide evidence that lipid core plaque detected by NIRS is also implicated in the most extreme presentation of acute coronary syndrome — sudden cardiac death. 

References

1. Myerburg RJ, Juntilla J. Sudden cardiac death caused by coronary heart disease. Circulation. 2012;125(8):1043-1052.
2. Burke AP, Farb A, Malcom GT, Liang Y, Smialek J, Virmani R. Coronary risk factors and plaque morphology in men with coronary disease who died suddenly. N Engl J Med. 1997;336(18):1276-1282.
3. Madder RD, Smith JL, Dixon SR, Goldstein JA. Composition of target lesions by near-infrared spectroscopy in patients with acute coronary syndrome versus stable angina. Circ Cardiovasc Interv. 2012;5(1):55-61.
4. Madder RD, Goldstein JA, Madden SP, et al. Detection by near-infrared spectroscopy of large lipid core plaques at culprit sites in patients with acute ST-segment elevation myocardial infarction. JACC Cardiovasc Interv. 2013;6(8):838-846.