Beta blockers should not be used as a first-line treatment in the acute setting for cocaine-induced acute coronary syndrome (CIACS). No recent studies have been identified that show the benefit of beta blockers in reducing coronary vasospasm, or coronary vascular resistance, in patients with CIACS. In the multiple case studies identified, the use of beta blockers in CIACS resulted in detrimental outcomes, and the discontinuation of beta blockers used in the acute setting led to improvement in clinical course. [ citation needed ] The guidelines by the American College of Cardiology/American Heart Association also support this idea, and recommend against the use of beta blockers in cocaine-induced ST-segment elevation myocardial infarction (MI) because of the risk of coronary vasospasm. [ citation needed ] Though, in general, beta blockers improve mortality in patients who have suffered MI, it is unclear whether patients with CIACS will benefit from this mortality reduction because no studies assess the use of beta blockers in the long term, and because cocaine users may be prone to continue to abuse the substance, thus complicating the effect of drug therapy.  Contrast media are not contraindicated in patients receiving beta blockers.