Cause:Multiple, including elevated cholesterol (Nejm 1981;304:65); smoking, passive (Nejm 1999;340:920) and active, correlates most w pack-years not w quitting (Jama 1998;279:119); hypertension; genetic, especially in women; Hgb A1C level >5 (Ann IM 2004;141:413, 421, 475). Possibly induced by Chlamydia pneumoniaeendovascular infection in cardiovascular disease (Jama 1999;281;427, 461though 1 wk rx w azithromycin to pts w stable CAD does not decr recurrence; Nejm 2005;352:1637, 1646, 1706), as well as vascular dementia (Jags 2005;53:583), or other causes of inflammation indicated by elevated CRP levels (Nejm 2002;347:1557, 1615; Jama 1999;282:2131, 2169) and interleukin-6 (Jama 2002;288:980); but no correlation between chlamydial IgG titers and ASHD found in women (Ann IM 1999;131:573)
Pathophys:(Nejm 1999;340:115) Wall stress causes fibrous plaques, which later infiltrate with cholesterol; impaired fibrinolysis may also play a role in genesis. Onset by age 18 yr (Nejm 1986;314:138). Hemorrhage into plaque causes sudden occlusions
Increased incidence in Western countries although it has decreased in last 25 yr, half due to decrease in risk factors and half due to medical rx (Nejm 1996;334:884) w improving post-MI survival (Nejm 1998;339:861)
Increased in diabetes, hypertension, obesity (Nejm 1990;322:882), inflammation as measured by sCRP and h/o acute infections (Nejm 2004;351:2599, 2611), air pollution (Nejm 2007;356:447), smokers perhaps via inflammation (CRP) and homocysteine levels (Ann IM 2003;138:891), pseudoxanthoma elasticum, myotonic dystrophy, alkaptonuria and ochronosis; homocystinuria/emia (Homocystinuria (Homocyst[e]inemia)) consumers of food w partially hydrogenated transfatty acids (Nejm 2006;354:1601); hyperlipidemias (Hyperlipidemias) especially LDL elevations often associated w apolipoprotein (epsilon) E4 allele (Jama 1994;272:1666), and w elevated lipoprotein () (Jama 1996;276:544); sleep disorders (Am J Med 2000;108:396); adults who were low-birth-weight children to age 2+ yr (Nejm 2005;353:1802, 1848).
Weak (ACP J Club 1998;129(2):50) or no association w triglyceride elevations alone, although they are markers for other risk factors (Nejm 1993;328:1220)
Decreased in moderate (7-20 drinks/wk) alcohol drinkers (Jama 1999;282:239; Nejm 1997;337:1705, Ann IM 1997;126:372, Nejm 1995;332:1245; 1993;329:1829), via increased TPA as well as HDL (Jama 1994;272:929) and flavins in red wine which appears to decr cancer mortality in addition (Ann IM 2000;133:411); in runners (Nejm 1980;303:1159), and otherwise regularly exercising men (Nejm 1998;338:94, 1993;328:533, 538, 574; 1993;329:1829) and women (Jama 2001;285:1447) via protective elevations of HDL cholesterol component; with high fiber diets (20+ gm qd) (Jama 1999;281:1995) like those high in fruits and vegetables (Ann IM 2001;134:1106); with increased fish intake of omega-3 or N-3 fatty acids (see Atherosclerosis); Mediterranean diet (Nejm 2003;348:2599)
Sx:Claudication, angina, MI, sudden death, TIA/CVA, abdominal angina
Si:Renal hypertension; bruits, absent peripheral pulses; CVAs; arcus senilis in Caucasians age <50 yr (Nejm 1974;291:1323) is a risk factor independent even of cholesterol levels (Am J Publ Hlth 1990;80:1200); retinal fundal vessel plaques, arterial narrowing correlates w MI risk in women but not men (Jama 2002;287:1153)
Lab:
Chem:Cholesterol (Hypercholesterolemia) Apolipoprotein A2 (Nejm 2000;343:1149) (components of HDL) may be better predictors
Hem: sCRP levels >1.55 mg/L, of doubtful utility (Nejm 2004;350:1450) but may ID candidates for primary statin preventive rx (Nejm 2008;359:2195, 2280)
Path:Lipid in foam macrophages and smooth muscle; free cholesterol crystals between intima and media
Xray:Electron beam CT screening of unproven value (Nejm 1998;339:1964, 1972, 2014, 2018)
Rx:
Prevent (Ann IM 2005;142:393)