Introduction: Chest pain is one of the cardinal manifestation that bring a patient to the emergency room or to a cardiologist;s clinic. However, such pain may originate not only in the heart but also from a variety of non-cardiac causes. People with undiagnosed Coronary Artery Disease are increasing, one could blame environmental factors or genetics. They often seek consult once chest pain set in and it is up to the physician to determine whether it is from cardiac or non-cardiac origin. Evaluation of a patient with chest pain in the emergency room is time consuming and expensive. This study was undertaken to assess the value of a simple bedside test, the NTG test, in the evaluation of patients who presents in the emergency room for initial episodes of chest pain.
Methods: A prospective cross sectional study that includes all patients who would come in at the ER for the first time presenting with the chest pain described as heaviness or squeezing, for more than six hours. Patient should be 20 years old and above from December 01, 2007 to November 30, 2008. Patient should not have a previous diagnosis of coronary artery disease. Patients must not have a prior intake of Nitroglycerin. Blood pressure should not be less than 80 mmHg prior to giving the drug. Patient not presently taking sildenafil. Clinical data from the ER, ECG, result of Troponin T and lipid profile will be noted. The initial step would involve identifying patients with headache and patients with non-headache after being given nitroglycerin 400mcg, sublingual. If the patient complains of headache, this will be labeled negative nitroglycerin test. Blood sample for Troponin T will be extracted. Patients with positive or negative nitroglycerin test will be referred for coronary angiogram to determine the severity of the coronary artery disease.
Result: The study was able to include thirty-five patients for analysis. Patients with NTG test positive or negative underwent coronary angiography. The mean age is 49, the oldest was 71 and the youngest was 6, 66% were males. All of the thirty-five patients underwent the NTG test. The NTG test showed 18 positive NTG test and 17 negative NTG test, prevalence of headache was 51%. Demographic and clinical characteristics of the patients showed 25 hypertensive patients, 13 smokers, 6 had a family history of coronary artery disease. 30 had abnormal ECG readings and 5 have no raedings. 11 patients showed high total cholesterol, 17 patients had normal total cholesterol levels, 10 patients had high LDL levels, 16 had normal LDL. 14 patients showed normal HDL levels, 12 patients had low HDL levels. All the thirty-five patients came in with chest pain, troponin T was requested and showed 2 positive Troponin T and 33 negative Troponin T. All of the thirty-five patients consented to undergo coronary angiography, 16 patients showed insignificant/significant coronary artery disease basing on the result of the confirmatory test while 19 had normal results.
Conclusion: Nitroglycerin test is a simple bedside procedure but a reliable predictor coronary artery disease. The validity measures of NTG test with Coronary angiography, which is the gold standard procedure in determining coronary artery disease, showed high sensitivity of 100% and a specificity of 89.5% with a Positive predictive value of 88.9% and Negative predictive value of 100%, P=0.000, wherein chi square analysis connotes a significant result.