title: Thermodilutional Confirmation of Coronary Microvascular Dysfunction in Patients With Recurrent Angina After Successful Percutaneous Coronary Intervention.
abstract: BACKGROUND
  Recurrent angina (RA) after percutaneous coronary intervention (PCI) remains a challenging problem that confronts cardiologists in routine clinical practice. In patients without epicardial coronary causes, RA is commonly speculated as resulting from coronary microvascular dysfunction. The aim of this study was to investigate the coronary microvascular function in patients with RA late after successful PCI and without epicardial stenosis at the time of repeat angiography.
  
  
  METHODS
  We studied 39 consecutive patients with RA in whom PCI was successfully performed 6 to 12 months previously because of angina and single-vessel disease and without restenosis and disease progression at the time of repeat angiography. Twelve subjects without RA were recruited as the control group. Thermodilution-derived coronary flow reserve (CFR) and index of microvascular resistance (IMR) were measured using a pressure-temperature sensor-tipped coronary wire. The exercise treadmill test was performed according to the Bruce protocol.
  
  
  RESULTS
  Patients with RA showed significantly higher IMR and lower CFR than control subjects, in the target arteries and in the reference vessels (P < 0.05). The hyperemic IMR was more remarkably increased in the target arteries than in the reference vessels (29.3 ± 11.7 vs 24.4 ± 9.7; P = 0.008). The hyperemic IMR was increased and the CFR was impaired more significantly in patients with a positive exercise treadmill test (P < 0.05).
  
  
  CONCLUSIONS
  Using an intracoronary thermodilution method, to our knowledge, we have for the first time confirmed that, in patients who underwent successful coronary stenting and without epicardial stenosis at repeat angiography late after PCI, coronary microvascular dysfunction was responsible for the RA.
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Daya
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Pathophysiology, Zhongshan Medical School, Sun Yat-sen University, Guangzhou, China.
authors.forename: Lihe
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Dexi
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Cardiac Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Yao
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Long
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. Electronic address: luochf@mail.sysu.edu.cn.
authors.forename: Chufan
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Cardiology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Du
mesh_terms: D000787:Angina Pectoris / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000503:physiopathology* / Q000601:surgery; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention; D011184:Postoperative Period; D011446:Prospective Studies; D013815:Thermodilution; D014655:Vascular Resistance / Q000502:physiology*