An increased vasopressor requirement may be associated with elevated mortality in acute myocardial infarction and cardiogenic shock (AMICS), and a decrease in the need for these drugs may enhance patient survival, according to authors of a study published in Catheterization and Cardiovascular Interventions.
Although vasopressors are frequently used for hemodynamic stabilization in AMICS, they are associated with adverse effects, including an increased left ventricular afterload. In the current study, researchers sought to evaluate the impact of vasopressors on survival in the National Cardiogenic Shock Initiative (ClinicalTrials.gov Identifier: NCT03677180), a single-arm, prospective, multicenter study evaluating the outcomes associated with early mechanical circulatory support in patients with AMICS treated with percutaneous coronary intervention (PCI).
Investigators at 57 US sites enrolled patients in the study between July 2016 and February 2019. Participants were 18 years or older and presented with acute MI within 12 hours of symptom onset, cardiogenic shock prior to PCI, and were treated with the Impella heart pump.
The total cohort included 300 patients; investigators had complete data for 267 of these participants. Overall, 37% of patients were taking no vasopressors after MCS and PCI; 43% were taking 1 vasopressor, and 20% were taking 2 or more vasopressors. The most commonly used vasopressors included norepinephrine, dopamine, and epinephrine (48%, 19%, and 13%, respectively).
In general, patients who required vasopressors were older, while other baseline characteristics were similar.
Investigators found that 67% of patients had shock on admission, while 19% presented with a witnessed out-of-hospital cardiac arrest with return of spontaneous circulation within 30 minutes, 30% had in-hospital cardiac arrest with return of spontaneous circulation within 30 minutes, 9% were in active cardiopulmonary resuscitation while MCS was being implanted, and 13% received therapeutic hypothermia.
Although 83% of patients received a continuous infusion of vasopressors prior to MCS and PCI, heart rate on presentation was 87±30 bpm and hemodynamics were poor (systolic blood pressure, 77.6±17 mmHg). Signs of tissue hypoperfusion and end-organ dysfunction were also present.
A majority of patients — 79% — presented with acute ST-elevation MI. Patients were revascularized promptly and median door-to-support time was 79 minutes (interquartile range [IQR], 52-117). Median door-to-balloon time was also 79 minutes (IQR, 54-117) in ST-segment elevation myocardial infarction. Ninety-three percent of patients achieved thrombolysis in myocardial infarction (TIMI) III flow in the culprit vessel following PCI.
Patients who had a cardiac power output (CPO) ≤0.6 W had survival rates of 77.3%, 45%, and 35.3% when 0, 1, or at least 2 vasopressors were used, respectively. Results were similar in patients with CPO ≥0.6 W: survival rates were 81.7%, 72.6%, and 56.8% for patients treated with 0, 1, and 2 or more vasopressors, respectively.
Study limitations include the observational design and a lack of both information on specific vasopressor doses and differentiation between vasopressors.
“Increasing requirements for vasopressors are associated with increasing mortality in AMICS irrespective of underlying CPO,” the researchers concluded. “Methods to decrease [the] need for vasopressors may enhance survival in AMICS.”
Disclosure: This clinical trial was supported by Abiomed and Chiesi Pharmaceuticals, Inc.
Basir MB, Lemor A, Gorgis S, et al; for the National Cardiogenic Shock Initiative Investigators. Vasopressors independently associated with mortality in acute myocardial infarction and cardiogenic shock. Catheter Cardiovasc Interv. Published online August 3, 2021. doi:10.1002/ccd.29895