Biomaterial Database

Estimating outcomes of astronauts with myocardial infarction in exploration class space missions. 2012

David B Gillis, and Douglas R Hamilton

University of Texas Medical Branch Galveston, Galveston, TX, USA. dgillis@ix.netcom.com

BACKGROUND We estimate likelihood of presenting rhythms and survival to hospital discharge outcome after acute cardiac ischemia with arrhythmia and/or myocardial infarction (AMI) during long-duration space missions (LDSM) using selected terrestrial cohorts in medical literature. Medical scenarios were risk-stratified by coronary artery calcium score (CAC) and Framingham risk factors (FRF). METHODS AMI with and without sudden cardiac arrest (SCA) likelihoods and clinically significant rhythm scenarios and associated outcomes in "astronaut-like" cohorts were derived from two prospective trials identified by an evidence-based literature review. Results are presented using an event sequence diagram and event time line. The association of increasing CAC scores and FRF with AMI and SCA outcomes was calculated. RESULTS Low AMI likelihoods are estimated in individuals with CAC scores of zero or < 100 and a low number of FRF. Survival rate to hospital discharge after out of hospital SCA in a large urban environment study was 5.2%. EMS-witnessed ventricular tachycardia and/or ventricular fibrillation survival rate of 37.5% represents < 1% of all urban out of hospital AMI, and these patients have a high proportion of known ischemic cardiovascular and pulmonary disease "disqualifying for spaceflight." CONCLUSIONS Multiple factors may be expected to delay or defeat rapid access to "chain of survival" resources during LDSM, lowering survival rates below urban levels of 5.2%. Low CAC and FRF reflect lower risk for AMI events. Zero CAC was associated with the lowest risk of AMI after 3.5 yr of follow-up. Quantifiable incidence and outcome characterization suggests AMI in LDSM outcomes will be relatively independent of in-flight medical resources.

UI	MeSH Term	Description	Entries
D009203	Myocardial Infarction	NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).	Cardiovascular Stroke,Heart Attack,Myocardial Infarct,Cardiovascular Strokes,Heart Attacks,Infarct, Myocardial,Infarction, Myocardial,Infarctions, Myocardial,Infarcts, Myocardial,Myocardial Infarctions,Myocardial Infarcts,Stroke, Cardiovascular,Strokes, Cardiovascular
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012307	Risk Factors	An aspect of personal behavior or lifestyle, environmental exposure, inborn or inherited characteristic, which, based on epidemiological evidence, is known to be associated with a health-related condition considered important to prevent.	Health Correlates,Risk Factor Scores,Risk Scores,Social Risk Factors,Population at Risk,Populations at Risk,Correlates, Health,Factor, Risk,Factor, Social Risk,Factors, Social Risk,Risk Factor,Risk Factor Score,Risk Factor, Social,Risk Factors, Social,Risk Score,Score, Risk,Score, Risk Factor,Social Risk Factor
D013026	Space Flight	Travel beyond the earth's atmosphere.	Space Exploration,Space Travel,Spaceflight,Exploration, Space,Explorations, Space,Flight, Space,Flights, Space,Space Explorations,Space Flights,Space Travels,Spaceflights,Travel, Space,Travels, Space
D014693	Ventricular Fibrillation	A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.	Fibrillation, Ventricular,Fibrillations, Ventricular,Ventricular Fibrillations
D015996	Survival Rate	The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.	Cumulative Survival Rate,Mean Survival Time,Cumulative Survival Rates,Mean Survival Times,Rate, Cumulative Survival,Rate, Survival,Rates, Cumulative Survival,Rates, Survival,Survival Rate, Cumulative,Survival Rates,Survival Rates, Cumulative,Survival Time, Mean,Survival Times, Mean,Time, Mean Survival,Times, Mean Survival
D016013	Likelihood Functions	Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.	Likelihood Ratio Test,Maximum Likelihood Estimates,Estimate, Maximum Likelihood,Estimates, Maximum Likelihood,Function, Likelihood,Functions, Likelihood,Likelihood Function,Maximum Likelihood Estimate,Test, Likelihood Ratio
D017023	Coronary Angiography	Radiography of the vascular system of the heart muscle after injection of a contrast medium.	Angiography, Coronary,Angiographies, Coronary,Coronary Angiographies
D017180	Tachycardia, Ventricular	An abnormally rapid ventricular rhythm usually in excess of 150 beats per minute. It is generated within the ventricle below the BUNDLE OF HIS, either as autonomic impulse formation or reentrant impulse conduction. Depending on the etiology, onset of ventricular tachycardia can be paroxysmal (sudden) or nonparoxysmal, its wide QRS complexes can be uniform or polymorphic, and the ventricular beating may be independent of the atrial beating (AV dissociation).	Idiopathic Ventricular Tachycardia,Nonsustained Ventricular Tachycardia,Paroxysmal Supraventricular Tachycardia,Ventricular Tachyarrhythmias,Ventricular Tachycardia,Idiopathic Ventricular Tachycardias,Nonsustained Ventricular Tachycardias,Paroxysmal Supraventricular Tachycardias,Supraventricular Tachycardia, Paroxysmal,Tachyarrhythmia, Ventricular,Tachycardia, Idiopathic Ventricular,Tachycardia, Nonsustained Ventricular,Tachycardia, Paroxysmal Supraventricular,Ventricular Tachyarrhythmia,Ventricular Tachycardia, Idiopathic,Ventricular Tachycardia, Nonsustained,Ventricular Tachycardias
D058687	Out-of-Hospital Cardiac Arrest	Occurrence of heart arrest in an individual when there is no immediate access to medical personnel or equipment.	Out-of-Hospital Heart Arrest,Cardiac Arrest, Out-of-Hospital,Cardiac Arrests, Out-of-Hospital,Heart Arrest, Out-of-Hospital,Heart Arrests, Out-of-Hospital,Out of Hospital Cardiac Arrest,Out of Hospital Heart Arrest,Out-of-Hospital Cardiac Arrests,Out-of-Hospital Heart Arrests