Smoky heart: cardiovascular manifestations of carbon monoxide poisoning

Abstract

Abstract Background Carbon monoxide (CO) poisoning is one of the most critical health concerns worldwide due to severe clinical effects with high morbidity and mortality. Tissue hypoxia and cellular damage from CO poisoning results in oxidative stress. Organs and tissues with high O2 demand including central nervous system (CNS) and cardiovascular (CV) system are the most susceptible to this oxidative stress. We investigate and describe the cardiovascular manifestations in 350 patients who were admitted for moderate to severe CO poisoning and treated with hyperbaric oxygen (HBO2) therapy. Purpose This study was conducted to identify the common cardiovascular manifestations of carbon monoxide poisoning. Methods We retrospectively collected data on 350 consecutive adult patients treated for CO poisoning between January 2011 to April 2018. Cardiac biomarkers, EKG and carboxyhemoglobin (COHb) levels were obtained from pre-hospital sources including EMS (emergency medical services) and from outside hospital records at the time of transfer. Glasgow Coma Scale (GCS) measurements were obtained at initial pre-hospital evaluation and upon arrival to the emergency room. Patient demographics, CV, CNS history and cardiac risk factors including hypertension, hyperlipidemia, diabetes, smoking history were obtained from electronic medical record. Myocardial injury was defined by cardiac troponin I level of ≥0.05 ng/mL. Results There were 350 patients admitted for CO poisoning from 2011 to 2018. 72% of the patients received HBO treatment due to severity of their symptoms. The mean age was 47.3 years with 60% men, 89% of the admissions were accidental exposure. Cardiac biomarkers were elevated in 40% of the patients and with 21% having sinus tachycardia. 6% had ischemic EKG changes with 23% having regional wall motion abnormalities on echocardiogram. In terms of intervention, 83% of the patients with elevated cardiac biomarkers received HBO treatment, 9% underwent coronary angiogram out of which 50% were candidate for either percutaneous intervention (PCI) or coronary artery bypass graft (CABG). In hospital mortality amongst this population was 2%. Conclusion Myocardial injury is common and widely seen with CO poisoning as seen by elevated cardiac biomarkers in 40% of the tested population. Initial work up for patients with CO poisoning should include evaluation with an EKG and serial biomarkers. If an abnormality is detected, patient should undergo an echocardiogram. Further evaluation with coronary angiography may be warranted in patients with new left ventricular dysfunction or wall motion abnormalities, especially in patients with risk factors. Funding Acknowledgement Type of funding sources: None.