Pre-operative homocysteine levels and morbidity and mortality following cardiac surgery

Abstract

AimsElevated homocysteinaemia is associated not only with an increased risk for cardiovascular disease but also for increased morbidity and mortality in patients with established coronary artery or cerebrovascular disease. Whether elevated homocysteine further increases the morbidity and mortality in patients undergoing cardiac surgery on cardiopulmonary bypass (CPB) (a prothrombotic state itself) remains less known.Methods and resultsAccordingly, we conducted a prospective observational study with pre-operative measurement of plasma homocysteine levels in 531 consecutive patients undergoing cardiac operations on CPB. The association of pre-operative plasma homocysteine levels with post-operative morbidity and hospital mortality was evaluated. Elevated homocysteine levels (>15 µmol/L) were observed in 209 patients (39.4%), and homocysteinaemia was associated with a higher mortality and perioperative morbidity (major morbidity, low cardiac output, acute renal failure, mesenteric infarction, and thrombo-embolic events). Even after accounting for the differences in baseline clinical features, EuroSCORE, and CPB time, pre-operative homocysteine levels remained independently associated with hospital mortality [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.03–1.11], major morbidity (OR 1.04, 95% CI 1.01–1.07), low cardiac output (OR 1.04, 95% CI 1.02–1.08), mesenteric infarction (OR 1.06, 95% CI 1.01–1.11), and thrombo-embolic events (OR 1.09, 95% CI 1.04–1.13). This association of homocysteine with increased risk of morbidity and mortality was observed particularly in CABG patients.ConclusionElevated pre-operative homocysteine level is independently associated with increased morbidity and mortality, particularly in patients undergoing CABG. Specific post-operative antithrombotic strategies may be advisable in hyperhomocysteinaemic patients.

Hyperhomocysteinemia abrogates fasting-induced cardioprotection against ischemia/reperfusion by limiting bioavailability of hydrogen sulfide anions

“…In patients undergoing scheduled cardiopulmonary bypass surgery, preoperative fasting is routinely recommended to prevent aspiration pneumonia, but its associated metabolic benefits have not been clarified [47]. Although hyperhomocysteinemia prior to bypass surgery was reported to be associated with increased mortality and morbidity [48], the mechanism or its impact in relation to fasting status is unknown. Further basic/ clinical studies are definitely warranted to disclose the relationship between fasting statuses, the in vivo levels/potential roles of homocysteine and reactive persulfide/polysulfide species, and their impacts on the degree of myocardial IR injury.…”

Homocysteine: An Emerging Cardiovascular Risk Factor that Never Really Made it~!2009-10-29~!2009-12-27~!2010-04-08~!

“…Elevated tHcy levels (> 15 μmol/l) were observed in 209 patients (39.4%) and hyperhomocysteinemia was associated with a higher mortality and peri-operative major morbidity (low cardiac output, acute renal failure, mesenteric infarction and thromboembolic events). In another prospective study (121 CAD patients undergoing CABG), preoperative tHcy levels were significantly related to the combined end point of death, nonfatal MI and bypass graft disease during a 2-year follow-up [54].…”

“…These result in relatively high operative and post-operative morbidity and mortality [51,52]. There appears to be a relationship between pre-operative tHcy levels and short-term (30-day) [53] and long-term (2-years) [54] postoperative CVD events in this high-risk group of CAD patients.…”

Does Correcting the Numbers Improve Long-term Outcome?

“…17 Nitrous oxide may also influence cardiac risk by increasing homocysteine levels. 18,19 Raised homocysteine levels predispose to higher cardiac risk in the community 20 and in cardiac surgical patients 21 via endothelial dysfunction and possible effects on coagulation. 19 Putatively related to this increased perioperative myocardial ischemia, increased homocysteine levels have been noted with nitrous oxide-based anesthesia (however, long-term follow-up of these patients has not been conducted).…”