Background:
The relationship between coronary vasodilator reserve and risk of coronary heart disease (chd) in subjects without coronary artery disease (cad) is not well known.
Methods and results:
We studied 289 subjects (mean age, 58 +/- 10 years) without overt cad and at low (< 10%) to intermediate risk (10%-20%) for chd based on framingham risk scores (rampart [relative and absolute myocardial perfusion changes as measured by positron emission tomography to assess the effects of acat inhibition: a double-blind, randomized, controlled, multicenter trial]). coronary flow reserve (cfr) and coronary vascular resistance (cvr) were calculated from rest and adenosine nitrogen 13 ammonia positron emission tomography studies. framingham-estimated chd risk was used to as a surrogate for outcomes. compared with subjects with low-risk scores (n = 150), those with intermediate-risk scores (n = 139) had a higher minimal cvr (49.3 +/- 17.41 mm hg x ml(-1) x min(-1) x g(-1) vs 52.4 +/- 16.4 mm hg x ml(-1) x min(-1) x g(-1), p = .05) and lower cfr (2.8 +/- 1.0 vs 2.5 +/- 0.8, p = .02). cfr was inversely related to chd risk (r = -0.2, p = .006), and cvr was directly related to chd risk (r = 0.2, p < .001). the mean cfr was significantly lower in patients in the first quartile of chd risk compared with those in the fourth quartile (2.3 +/- 0.7 vs 2.8 +/- 1.0, p = .02), and the minimal cvr was significantly higher (44 +/- 15 mm hg x ml(-1) x min(-1) x g(-1) vs 53 +/- 14 mm hg x ml(-1) x min(-1) x g(-1), p < or = .05).
Conclusions:
In subjects without clinical cad and at low to intermediate risk, cfr assessed by positron emission tomography is inversely related to estimated 10-year chd risk.