Effect of the angiotensin receptor blocker Valsartan on coronary microvascular flow reserve in moderately hypertensive patients with stable coronary artery disease.
OBJECTIVE
To noninvasively investigate the effects of the angiotensin receptor blocker (ARB) Valsartan. on myocardial microcirculation in moderately hypertensive patients with stable coronary artery disease (CAD).


RESULTS
In this prospective open-label study, patients with mild stable CAD and moderate systolic and/or diastolic hypertension were treated with 160 mg Valsartan daily. Myocardial blood flow was quantified noninvasively using positron emission tomography (PET) with N-13 ammonia at baseline, after one week and after 16 weeks. Mean blood pressure at rest improved significantly from baseline to week 16 (105 +/- 10 vs. 98 +/- 9 mm Hg: p = 0.017, n = 12), but no significant change was observed after one week (103 +/- 11 vs. 100 +/- 11, p = 0.43, n = 13). PET analysis revealed that flow increase during endothelial-dependent, sympathetic stimulation by cold pressor testing (CPT) and in response to pharmacologic vasodilation with adenosine improved from baseline after 1 week (CPT: 1.10 +/- 0.3 vs. 1.37 +/- 0.3; p = 0.017, adenosine: 2.34 +/- 0.52 vs. 2.91 +/- 0.81; p = 0.048) and at week 16 (CPT: 1.15 +/- 0.4 vs 1.39 +/- 0.2; p = 0.10, adenosine: 2.34 +/- 0.52 vs 2.81 +/- 0.91; p = 0.039).


CONCLUSIONS
In patients with stable coronary disease, ARB results in improved PET-determined microvascular flow reserve. Improvements in microcirculation preceded the reduction of blood pressure, suggesting direct beneficial effects on microvascular function.
Higuchi
Takahiro
T
Nuklearmedizinische Klinik und Poliklinik der Technischen Universität München, Klinikum rechts der Isar, Munich, Germany.
Abletshauser
Claudia
C
Nekolla
Stephan G
SG
Schwaiger
Markus
M
Bengel
Frank M
FM
D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage*; D000959:Antihypertensive Agents / Q000008:administration & dosage; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D053805:Fractional Flow Reserve, Myocardial / Q000187:drug effects*; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D011859:Radiography; D013777:Tetrazoles / Q000008:administration & dosage*; D014633:Valine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000068756:Valsartan
D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine