Objectives Our aim was to investigate the safety and efficacy of intravenous allogeneic human mesenchymal stem cells (hMSCs) in patients with myocardial infarction (MI). Background Bone marrow-derived hMSCs may ameliorate consequences of MI, and have the advantages of preparation ease, allogeneic use due to immunoprivilege, capacity to home to injured tissue, and extensive pre-clinical support. Methods We performed a double-blind, placebo-controlled, dose-ranging (0.5, 1.6, and 5 million cells/kg) safety trial of intravenous allogeneic hMSCs (Prochymal, Osiris Therapeutics, Inc., Baltimore, Maryland) in reperfused MI patients (n = 53). The primary end point was incidence of treatment-emergent adverse events within 6 months. Ejection fraction and left ventricular volumes determined by echocardiography and magnetic resonance imaging were exploratory efficacy end points. Results Adverse event rates were similar between the hMSC-treated (5.3 per patient) and placebo-treated (7.0 per patient) groups, and renal, hepatic, and hematologic laboratory indexes were not different. Ambulatory electrocardiogram monitoring demonstrated reduced ventricular tachycardia episodes (p = 0.025), and pulmonary function testing demonstrated improved forced expiratory volume in 1 s (p = 0.003) in the hMSC-treated patients. Global symptom score in all patients (p = 0.027) and ejection fraction in the important subset of anterior MI patients were both significantly better in hMSCs versus placebo subjects. In the cardiac magnetic resonance imaging substudy, hMSC treatment, but not placebo, increased left ventricular ejection fraction and led to reverse remodeling. Conclusions Intravenous allogeneic hMSCs are safe in patients after acute MI. This trial provides pivotal safety and provisional efficacy data for an allogeneic bone marrow-derived stem cell in post-infarction patients. (Safety Study of Adult Mesenchymal Stem Cells [MSC] to Treat Acute Myocardial Infarction; NCT00114452)

Ejection fraction, ESVI and IS measurements performed one to two weeks after MI can each predict six-month mortality. Ejection fraction was superior to the other two measurements. However, this study had limited power to detect independent significance of ESVI or IS.

ONTRAST-INDUCED NEPHROPAthy, which occurs in 1% to 15% of all patients undergoing invasive angiographic procedures and in as many as 50% of patients with preexisting renal insufficiency or diabetes mellitus, is one of the most common causes of hospitalacquired acute renal failure. [1][2][3][4][5][6][7] The development of contrast-induced nephropathy after diagnostic coronary angiography and percutaneous intervention is associated with prolonged hospitalization, marked increases in morbidity and early and late mortality, and costs. [4][5][6][7][8] Other than hydration, 9,10 most prior studies of measures to prevent contrast-induced nephropathy have either been neutral, 11 found deleterious effects, [12][13][14][15] or in the case of N-acetylcysteine, reported conflicting results. [16][17][18][19]

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