Abstract P014: Methamphetamine Associated Cardiomyopathy is Associated with Impaired Myocardial Energy Usage via 31Phosphorus Magnetic Resonance Spectroscopy
Introduction: Methamphetamine and related stimulants are now the second most abused illicit drugs worldwide. Methamphetamine associated cardiomyopathy (MAC) has been increasingly reported but still poorly characterized in comparison with other drug-induced cardiomyopathies.
Hypothesis: Persons with MAC may have left ventricular structural changes as well as altered myocardial energy as compared to persons with ischemic cardiomyopathy or with no known cardiomyopathy.
Methods: Male persons (mean age=48.2) with MAC (n=10) were selected from a clinic setting. Inclusion criteria included LVEF < 35% on echocardiogram in the past year. Cases were divided into all and current methamphetamine users (n=4). Two sets of controls included: persons 1) free of known cardiomyopathy (n=8) and 2) with ischemic cardiomyopathy (n=6), also with LVEF < 35% on echocardiogram within the past year.
Subjects underwent cardiac magnetic resonance imaging (cMRI) at 3 Tesla with Siemens TIM TRIO MRI to assess LV mass and volumes. Subjects then underwent 2 dimensional Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) to obtain phosphocreatine (PCr) to adenosine triphosphate (ATP) ratios in the LV anterior wall to assess cardiac energetics. Results were analyzed with the unequal variance t-test.
Results: We found a statistically significant difference in PCr: ATP ratios in the current methamphetamine users when compared to normal controls (p=0.03), a result not seen in the ischemic group (p=0.49). A trend towards lower PCR to ATP ratios was seen in all methamphetamine users compared to normal controls (p=0.06). Compared with normal controls, persons with MAC had larger LV diastolic volumes (p=0.004) while persons with ischemic cardiomyopathy were similar (p=0.11) (Table).
Conclusion: Methamphetamine usage is associated with impaired myocardial energy, beyond that seen in ischemic cardiomyopathy with comparable LV EF. Structurally, MAC is associated with larger LV diastolic volumes than ischemic cardiomyopathy.
- © 2013 by American Heart Association, Inc.