The traditional Chinese herbal medicine tongxinluo added to guideline-directed therapy improves clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI), the CTS-AMI study suggests.
Compared with placebo, Chinese patients assigned to tongxinluo had lower rates of 30-day and 1-year major adverse cardiovascular and cerebrovascular events (MACCE), driven by fewer cardiac deaths. Severe STEMI complications were also lower.
Tongxinluo, which contains 10 or more potential active herbs and insects, did not result in severe adverse effects, including major bleeding.
The results were presented today at the American Heart Association (AHA) Scientific Sessions 2022 by Yuejin Yang, MD, PhD, a professor of cardiology at Fuwai Hospital, National Center for CV Disease, Beijing, China.
He noted that despite reperfusion and optimal medical therapy, patients with STEMI still face high in-hospital mortality, myocardial no-flow, and reperfusion injury, which have no targeted drugs so far worldwide. In addition, “inadequate implementation of timely revascularization for STEMI in China (50-70%) and other developing countries leaves a substantial infarct size in many patients.”
Tongxinluo has been approved for angina and stroke since 1996 in China. Previous preclinical studies and the investigators’ proof-of-concept ENLEAT trial in STEMI suggested tongxinluo could reduce myocardial no-flow and infarction size and protect the cardiomyocytes, Yang said.
The CTS-AMI trial was conducted at 124 hospitals in mainland China and evenly randomly assigned 3797 patients with STEMI or new left bundle-branch block within 24 hours of symptom onset to 8 capsules of tongxinluo, 2.08 g, or to placebo plus dual antiplatelet therapy before percutaneous coronary intervention (PCI), thrombolysis, or medical management alone, followed by 4 capsules thrice daily plus guideline-directed therapy for 12 months.
In the modified intention-to-treat cohort of 1889 tongxinluo- and 1888 placebo-treated patients, primary PCI was performed in 94.2% and 92.3%, respectively.
The relative risk (RR) of 30-day MACCE was reduced 36% in the tongxinluo group compared with the placebo group (3.39% vs 5.24%; RR, 0.64; 95% CI, 0.47 – 0.88).
Among the primary endpoint components, the relative risk of cardiac death was reduced 30% (2.97% vs 4.24%; RR, 0.70; 95% CI, 0.50 – 0.99) and MI reinfarction 65% (0 vs 9 events; RR, 0.35; 95% CI, 0.13 – 0.99).
Strokes were similar in the tongxinluo and control groups (4 vs 9; RR, 0.44; 95% CI, 0.14 – 1.43) and no patient had emergent coronary revascularization at 30 days.
The benefit of the traditional Chinese compound on the primary endpoint was consistent across subgroups, Yang reported.
At 30 days, severe STEMI complications (11.79% vs 14.80%; P = .008) and malignant arrhythmias (7.84% vs 10.20%; P = .011) were lower in the tongxinluo group, whereas mechanical complications (10 vs 13; P = .526) and cardiogenic shock (2.37% vs 3.31%; P =.082) were similar.
At 1 year, hazard ratios favored tongxinluo for MACCE (0.64; 95% CI, 0.49 – 0.82), cardiac death (0.73; 95% CI, 0.55 – 0.97), MI reinfarction (0.26; 95% CI, 0.10 – 0.67), and stroke (0.44; 95% CI, 0.21 – 0.92).
In terms of safety issues, 41 patients receiving tongxinluo and 52 patients receiving placebo had a serious adverse event (2.17% vs 2.75%; P = .25).
Except for fewer renal injuries with tongxinluo (3.81% vs 5.30%; P = 029), there were no significant between-group differences in allergic rash, hepatic injury, prolonged activated partial thromboplastin time or prothrombin time, digestive tract hemorrhage, nausea, diarrhea, and headache or dizziness.
“These findings support the use of tongxinluo as an adjunctive therapy in treating STEMI, at least in China and other developing countries,” Yang concluded.
Invited discussant Kenneth Mahaffey, MD, associate dean, Stanford School of Medicine and director of the Stanford Center for Clinical Research, California, said the results “likely will support use of tongxinluo in China” but that “more studies are needed in other populations and treatment paradigms.”
Asked for further comment by theheart.org | Medscape Cardiology, Mahaffey said, “The surprising thing is where are all the MIs? Where are all the revascularization procedures?”
Usually one would expect MIs in about 1% of patients, or about 40 MIs among the 4000 patients but, he noted, there were zero MIs in the treatment group and 9 among controls.
“We haven’t seen a 30% reduction in cardiovascular death or overall mortality with a therapy in ages with good background therapy,” Mahaffey said. “We need to see how they ascertained all those events.”
He noted that the results were based on the modified intention-to-treat cohort, which did not include data on 20 patients allocated to treatment, and showed no difference in ST-segment resolution at 2 hours and only a slight difference at 24 hours.
“So even in this trial, for at least some of the data we’ve gotten already that supports the proposed mechanism, it doesn’t show the benefit on that mechanistic substudy. And that’s why we need to see these echos, the biomarkers, and probably the angios to see: did it have any effect on the proposed mechanism?” Mahaffey said.
Finally, information on background therapy is critical for putting the treatment effect into context for other health systems and populations, he said. “Unfortunately, we need to see some additional information to really understand how this will fit in, even in Chinese therapy for STEMI patients, but definitely not outside of China, particularly in the United States, because I don’t know what their background therapy was.”
The study was funded by the National Key Research and Development Program of China. Tongxinluo and placebo were provided by Yiling Pharmacological Co. The study was designed, conducted, and analyzed independent of the sponsors. Yang reports no relevant financial conflicts of interest. Mahaffey reports research funding from the AHA, Apple, Bayer, CIRM, Eidos, Ferring, Gilead, Idorsia, Johnson & Johnson, Luitpold, PAC-12, Precordior, Sanifit, and Verily; consultancy fees from Amgen, Applied Therapeutics, AstraZeneca, CLS Behring, Elsevier, Fibrogen, Inova, Johnson & Johnson, Lexicon, Myokardia, Novartis, Novo Nordisk, Otsuka, Phasebio, Portola, Quidel, Sanofi, and Theravance; and equity in Precordior.
American Heart Association (AHA) Scientific Sessions 2022. Abstract 2022-LBS-19508-AHA. Presented November 6, 2022.
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