Unfavorable Outcome of Percutaneous Coronary Intervention for Coronary Heart Disease with Rare Severe Pericoronary Fat Stranding

Background: Pericoronary fat stranding (PCFS) is a novel noninvasive imaging sign of coronary inflammation, and has important implications for cardiovascular risk stratification, and the outcome of percutaneous coronary intervention (PCI) for coronary heart disease patients with pericoronary fat stranding remains unknown. Aim: We report two rare cases of PCI-treated coronary heart disease patients with severe PCFS. Case Presentation: This is the first report of two rare cases of PCI for patients with coronary heart disease surrounded by severe PCFS. We demonstrated that the outcome in these cases is poor, and in-stent restenosis or occlusion occurs rapidly within 2- 6 months following PCI. However, Case 2 underwent coronary artery bypass grafting after the rapid occurrence of in-stent occlusion, and the bypass graft remained intact over the 5 years following coronary artery bypass grafting. Conclusion: Coronary artery bypass grafting rather than PCI may be appropriate for coronary heart disease patients with severe PCFS.

World Journal of Cardiovascular Diseases, by an abnormally increased CT attenuation of pericoronary fat, occurring as a manifestation of edema, inflammation or neoplastic infiltration [1]. Recent studies have shown that PCFS is closely associated with coronary inflammation, vulnerable plaques, plaque progression and cardiovascular events, and PCFS can be a potential imaging biomarker to monitor the anti-inflammation response to statin treatments [1] [2] [3]. However, the outcome of percutaneous coronary intervention (PCI) for coronary heart disease patients with PCFS remains unknown. We report two rare cases of PCI-treated coronary heart disease patients with severe PCFS.

Case 1
A 63-year-old female initially presented to our hospital with repeated retrosternal crushing pain. She reported a 5-year history of hypertension which was well controlled; she denied any history of diabetes, smoking, drinking of alcohol, allergies and familial genetic diseases. On admission, her ECG showed abnormal Q waves in leads III and avF ( Figure 1). The laboratory examination showed: an elevated hypersensitive cardiac troponin I of 1.80 µg/L, total cholesterol of 5.66 mmol/L, low density lipoprotein of 3.54 mmol/L, hypersensitive C-reactive protein of 4.9 mg/L, and erythrocyte sedimentation rate of 32 mm/h. Coronary computed tomography angiography (CCTA) demonstrated occlusion in the proximal left anterior descending (LAD) artery with severe PCFS, moderate stenosis in the proximal left circumflex (LCX) artery with PCFS, and no lesion in the right coronary artery (RCA) (Figures 2(a)-(d)). The LAD was then treated with a drug-eluting stent, and her symptoms resolved. However, 2 months later, the patient was admitted to our hospital with a recurrence of retrosternal paina   (Figure 2(g)), On several occasions, coronary artery bypass grafting was suggested to the patient, but she refused, and following this, the patient was admitted to hospital 9 times, once every 2 -6 months, due to repeated and rapid in-stent restenosis or occlusion. Moreover, CCTA during her 4th hospital admission (14 months after the initial hospital admission) showed new and severe PCFS with severe stenosis in the proximal RCA (Figures 2(h)-(i)). The patient underwent re-implantation stent, balloon angioplasty including drug-coated balloon, and reinforcement drug treatment including PCSK9, but the outcomes H. Hui et al.
were not good.

Case 2
A 55-year-old female initially presented to our hospital with intermittent precordial crushing pain. She reported a 4-year history of hypertension which was well controlled; she denied any history of diabetes, hyperlipidemia, smoking,  (Figures 4(a)-(c)). The LMA, LAD and LCX arteries were treated with drug-eluting stents, and her symptoms resolved. However, 3 months later, she was admitted to our hospital with precordial painagain, and subsequent catheterization angiography showed rapid progression to in-stent occlusion in the LMA, LAD and LCX (Figure 4(d)). Therefore, coronary artery bypass grafting was then performed for the LAD, diagonal branch and LCX. One year later, follow-up CCTA indicated all three grafts were intact, and there was new mild PCFS and stenosis in the proximal RCA (Figure 4(e)). Four years later, both CCTA and catheterization angiography during her 3rd hospital admission indicated all three grafts were still intact, while the PCFS in the RCA had significantly increased with the severe progression of the stenosis. The RCA was then treated with a drug-eluting stent (Figures 4(f)-(h)).

Discussion
This is the first report of cases of PCI for rare patients with coronary heart disease surrounded by severe PCFS. We demonstrated that the outcome in these cases maybe poor, and in-stent restenosis or occlusion occurs rapidly within 2 -6 months following PCI.
In Case 1, multiple therapies were tried following PCI, but they failed to arrest the rapid development of in-stent restenosis. The mechanism at work may be that proinflammatory adipokines and cytokines were secreted as a byproduct of the PCFS, and these directly diffused into the vascular walls due to the lack of a fascial plane, and this induced atherosclerosis-vascular inflammation, further causing in-stent atherosclerosis and restenosis [4]. Case 2 differs from Case 1 in that Case 2 underwent coronary artery bypass grafting after the rapid occurrence of in-stent occlusion, and the bypass graft remained intact over the 5 years following coronary artery bypass grafting. Another interesting finding is that in 2 Cases, severe PCFS was observed initially in the LAD and LCX arteries, and then PCFS in the RCA occurred about 1 year later. Furthermore, PCFS increased over time, accompanied by the rapid progression of stenosis.

Conclusion
We suggested that the outcome of PCI-treated coronary heart disease patients with uncommon severe PCFS is poor, and coronary artery bypass grafting may be appropriate for these patients. Furthermore, severe PCFS is ultimately prone to involve all three coronary arteries. Further study should be required to confirm and refine our findings.