Xuedong AN, Lina M, Ping X, et al. Effects of Shengmai Yin (生脉饮) on pulmonary and cardiac function in coronavirus disease 2019 convalescent patients with cardiopulmonary symptoms: a randomized, double blind, multicenter control trial. J Tradit Chin Med. 2023;43(1):140-145.
To evaluate the safety and efficacy of Shengmai Yin using a visual analog scale (VAS) for cardiopulmonary symptoms in Covid-19 convalescent patients
Shengmai Yin formula may be an easy and beneficial intervention to improve the quality of life of convalescent patients with Covid-19, specifically when it comes to alleviating patients’ chest distress symptoms.
Randomized, double-blind, multicenter, controlled trial
The study involved 200 Covid-19 convalescent patients with cardiopulmonary symptoms at 3 medical centers: 100 patients in the trial group (men=41; women=59) and 100 patients in the control group (men=31; women=69). Of those, 192 patients completed the trial (98 in the trial group and 94 in the control group).
Inclusion criteria: no fever for at least 72 hours, clinical remission of respiratory symptoms, substantial improvement in both lungs on chest computed tomography (CT), and 2 negative throat swabs for SARS-CoV-2 RNA at least 24 hours apart. Additional criteria: (a) 2 to 3 symptoms or at least 1 symptom with VAS score greater than 4; (b) 2 to 4 weeks since hospital discharge; (c) aged 18 to 70 years; and (d) signed informed consent.
Exclusion criteria: (a) patients with difficulty taking oral medication due to underlying conditions; (b) underlying conditions affecting survival (uncontrolled heart, lung, kidney, digestive, hematologic, neuropsychiatric, or immunological conditions; metabolic disease; malignancies; severe malnutrition); (c) allergic predisposition, allergies to the medications included in treatment plan; (d) pregnancy or lactation; (e) mental illness, altered mental state, deficiencies in communication, or lack of self-awareness, and (f) participation in other clinical trials.
Patients took 10 mL of Shengmai Yin (Tong Ren Tang Technologies Co.) 3 times a day for 2 weeks.
Study Parameters Assessed
Investigators assessed the following symptoms on VAS, scored from 0 to 10 depending on severity at 0, 1, and 2 weeks:
- shortness of breath,
- chest distress,
- palpitations, and
- dry cough.
Primary Outcome Assessed
Investigators defined a decrease in VAS of 30% or more as effective. They defined a reduction in VAS to 0 as curative.
Shengmai Yin treatment was effective for alleviating chest distress (P=0.008). There was no significant difference in shortness of breath, hidrosis, palpitations, and dry cough at 2 weeks.
Investigators did not note any disclosures or study funding sources.
Practice Implications & Limitations
Shengmai San is a popular traditional Chinese medicine (TCM) formula containing 3 ingredients: Radix ginseng, Radix ophiopogonis, and Fructus schisandrae. It can be administered as a liquid (Shengmai Yin, which was used in this study), Shengmai capsule or granule, or via a modern application of the formula as an intravenous infusion (used in China). It is a qi and yin tonic and is frequently given to patients in a recovery phase when they are weakened by a serious illness to help them regain strength. Shengmai means “to restore or generate pulse” and is expected to improve the strength and quality of the patients’ pulse, which reflects overall improvement in their condition and vitality.
Shengmai formulas have shown significant benefits in cardiovascular and respiratory illnesses and have been reviewed extensively in the literature.1,2 Some of its actions include positive benefits in heart failure,3 dilated cardiomyopathy,4 and improved respiratory function in chronic obstructive pulmonary disease (COPD).5 The varied research behind Shengmai Yin makes it a logical choice for treatment of Covid-19 patients, who exhibit significant strain on both cardiovascular and respiratory functions, among others.
Higher dosing may have improved the outcome.
The study lasted for 2 weeks and analyzed patients’ responses in 5 areas: shortness of breath, hydrosis, chest distress, palpitations, and dry cough. Only chest distress showed a statistically significant improvement on the self-reported VAS score. No major adverse effects were noted. Several reasons can account for why only 1 out of 5 symptoms improved, including: dosing, mode of administration, study duration, comorbidities, and monitoring parameters.
Higher dosing may have improved the outcome. The patients in this study received 10 mL of the formula 3 times a day for a period of 2 weeks for a total dose of 30 mL a day. Another small trial of patients with dilated cardiomyopathy used 20 mL formula twice daily for a total dose of 40 mL per day; this study found an increased exercise tolerance, as well as improved left ventricular contractility in the patient population.
The method of administration and combination with other therapies can also play a role in the result. The study duration of only 2 weeks has been done in the past, but those studies employed an intravenous preparation of the formula, therefore avoiding first-pass effect in the body. Oral therapies usually need more time to reach the target sites.
In a small study of 20 patients with COPD, those treated with an intravenous preparation of Shengmai formula for a total of 14 days had improved respiratory function.5 Shengmai injections after acute myocardial infarction also showed promise when combined with conventional therapies. While caution is warranted regarding the methodology and small sample size of the trials, the review nevertheless showed a trend toward decreased fatality rate during hospitalization and a decrease in the incidence of cardiac failure, shock, and re-infarction.6
We have seen clinically how Covid-19 severity varies among different individuals. While the study excluded certain life-threatening imminent conditions that affect survival, many factors that can play a role in the disease progression and recovery are unaccounted for in this study. Some of these factors are related to the virus itself, such as the severity of infections caused by different strains of SARS-CoV-2 infections. Some factors are related to host and environmental factors: lifestyle, diet, activity levels, habits, genetics, body composition status, vitamin D status, underlying chronic conditions, coinfections, and environmental factors, such as climate and air pollution, as well as cultural and socio-economic factors.7
Overall, this study supports a short-term, safe use of Shangmai Yin as a quality-of-life intervention in convalescent Covid-19 patients. More studies utilizing quantifiable clinical tools, such as laboratory and imaging studies to measure cardiovascular, respiratory, and immune response, would be helpful to establish further efficacy of the formula in a clinical setting.