Episode 215: Meth-associated HFrEF.  

Abishak and Zat (medical students) explain the cardiotoxic effect of methamphetamine and the diagnosis and treatment of heart failure with reduced ejection fraction (HFrEF). Dr. Arreaza adds insight into the reversibility of meth-associated HFrEF.  

Written by Abishak Govindarajan, MSIV and Zat Akbar Shaw. American University of the Caribbean. Edits and comments by Hector Arreaza, MD.

Welcome

Dr. Arreaza: Welcome to Rio Bravo qWeek. My name is Hector Arreaza, family physician, faculty and associate program director of the Clinica Sierra Vista/Rio Bravo Family Medicine Residency Program. Today we will explore heart failure with reduced ejection fraction, a high-yield and clinically relevant topic in medicine. We will discuss the role of methamphetamine use in the development of HFrEF. This is a pressing issue because about 0.8% of the population 12 and older in the US reported using methamphetamine within the past 12 months in 2024 (National Survey on Drug Use and Health, NSDUH), that’s about ≈2.4 million people!We are joined by two aspiring physicians who will help explore this topic. By the way, we will refer to methamphetamine in this episode as “meth”. [Abishak and Akbar introduce themselves]

Abishak: [Introduce yourself]

The role of meth in HFrEF
Dr. Arreaza: Meth is a growing problem in many places, including Bakersfield, where we live. Meth is also known as Meth Crystal, Poor man’s cocaine, Ice, Glass, Crank, Speed, Chalk, and Tina. How does meth contribute to the development of HFrEF?
Abishak: So, first, let's understand how methamphetamine works. It has a chemical structure similar to dopamine and norepinephrine, and it gets taken up through the neuron transporter proteins. Once it enters the synaptic vesicles (storage sacs for neurotransmitters), it displaces and forces the release of large amounts of dopamine, norepinephrine, and serotonin into the synapse (the space between neurons). Additionally, meth blocks the reuptake of those neurotransmitters into the neuron, ensuring they remain in the synapse for a prolonged period. All this causes a downstream effect of increased sympathetic pathways in the body.

Diagnosis
Dr. Arreaza: The diagnosis starts with collecting a good history and performing a complete physical exam, and then we confirm with an echocardiogram. 

Abishak: Yes, diagnosis requires both symptoms consistent with heart failure and objective evidence of reduced ejection fraction. Echocardiography is the primary diagnostic tool. We also measure BNP. In certain cases, cardiac MRI is used to evaluate myocardial fibrosis and exclude infiltrative or inflammatory etiologies. Coronary angiography may be performed if ischemic disease is suspected.
Guideline-Directed Medical Therapy
Dr. Arreaza: GDMT Guideline-Directed Medical Therapy started around 1987 when ACE inhibitors were proven to improve mortality in patients with heart failure. Then, during the following decades, many medications have been added to GDMT. Until around 2019–2022 we came out with the main 4 groups of medications that we know as GDMT. Let’s talk about GDMT.

Akbar: There are four core pillars in GDMT.
First, an angiotensin receptor-neprilysin inhibitor, such as sacubitril with valsartan (Entresto), is preferred over ACE inhibitors when tolerated. This medication reduces mortality and heart failure hospitalizations.
Second, evidence-based beta blockers including carvedilol, metoprolol succinate, or bisoprolol are used to reduce sympathetic overactivity and improve ventricular remodeling.
Third, mineralocorticoid receptor antagonists such as spironolactone or eplerenone reduce fibrosis and improve survival.
The Fourth pillar is SGLT2 inhibitor