Relation between cardiovascular risk factors and coronary microvascular dysfunction in cardiac syndrome X.
BACKGROUND
The causes of coronary microvascular dysfunction (CMVD) in patients with cardiac syndrome X (CSX) are largely unknown. Common cardiovascular risk factors (CVRFs) and increased markers of inflammation have been associated with CMVD in some studies, but their role in determining CMVD in CSX patients remains poorly known.


RESULTS
We studied 71 CSX patients (56 ± 9 years, 23 men) and 20 healthy volunteers (52 ± 7 years, nine men). Using transthoracic Doppler echocardiography, coronary microvascular vasodilator function was assessed in the left anterior descending coronary artery as the ratio of diastolic coronary blood flow (CBF) velocity at peak intravenous adenosine administration and during cold pressor test (CPT) to the respective basal CBF velocity values. Common CVRFs tended to be more frequent and C-reactive protein (CRP) levels were higher (P < 0.001) in CSX patients than in controls. Both CBF responses to adenosine (2.05 ± 0.6 vs. 2.92 ± 0.9, P < 0.001) and to CPT (1.71 ± 0.6 vs. 2.42 ± 0.7, P < 0.001) were lower in CSX patients than in controls. The differences between the two groups in CBF response to adenosine and in CBF response to CPT remained highly significant (P < 0.01 for both) after adjustment for all CVRFs, including serum CRP levels.


CONCLUSIONS
In CSX patients, both endothelium-dependent and endothelium-independent CMVD cannot be reliably predicted by CVRFs (including serum CRP levels), alone or in combination.
Institute of Cardiology, Catholic University of the Sacred Heart, Rome, Italy.
Alfonso
A
Sestito
Gaetano A
GA
Lanza
Antonio
A
Di Monaco
Priscilla
P
Lamendola
Giulia
G
Careri
Pierpaolo
P
Tarzia
Gaetano
G
Pinnacchio
Irma
I
Battipaglia
Filippo
F
Crea
D000241:Adenosine; D000368:Aged; D001783:Blood Flow Velocity; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D003080:Cold Temperature; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D007558:Italy; D008297:Male; D008833:Microcirculation; D017566:Microvascular Angina / Q000000981:diagnostic imaging / Q000209:etiology / Q000276:immunology / Q000503:physiopathology*; D055806:Microvessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors; D014664:Vasodilation; D014665:Vasodilator Agents
D018836:Inflammation Mediators; D014665:Vasodilator Agents; D002097:C-Reactive Protein; D000241:Adenosine