Stimulated by Jung et al 2020.
It is somewhat ironic that last week I rather dismissed a paper on acupuncture in hypertension and the fMRI activation findings associated with certain points, and just a few days later we publish this huge retrospective cohort study on acupuncture and MACE in hypertension.
I don’t recall seeing the acronym MACE before, but I guess it is part of the terminology used within these huge healthcare databases. It will be higher up the tree of terms from those conditions we are more familiar with as clinicians: myocardial infarction (MI), stroke and death!
I have highlighted most of the large retrospective cohorts related to the use of acupuncture in this blog, and they can be found by selecting ‘Retrospective cohorts’ from the category list of this blog.
We have 5 or 6 from Taiwan, where they have most of the 23 million population on their National Health Insurance Research Database. There is one from the US on opioid prescription in back pain, one from Thailand on survival in stroke, and now this makes the third such study from Korea.
Korea has a population of 50 million, and they have a research database formed out of a random sample of 2% of the population, so the start point is one million individuals. Jung et al identified 59 370 patients taking anti-hypertensive drugs who had been diagnoses with HT between 2003 and 2006. Of these, 18 044 had received more than 2 sessions of acupuncture within a year of diagnosis. After propensity score matching the number in each group was 18 011, so presumably 33 patients having acupuncture could not be matched.
The MACE outcomes were those of interest, and then it was just a matter of observing the differences in these two large groups of similar patients. The term used is a hazard ration (HR), and if it is less than 1 that means the group of interest has fewer cases than the comparator (the matched cohort).
The analysis has been performed in a number of different ways. We have a crude (unadjusted) comparison, a multivariable analysis (adjusted for 5 key variables), the propensity score matched (PSM) analysis (this was the primary outcome of interest) and, wait for it, an inverse probability of treatment weighting analysis. That last one is a bit hard to conceptualise, but essentially, I think they calculated probability of MACE outcomes from the PSM and then used that to adjust the crude figures from the pre-PSM cohort of close to 60k patients.
As you might imagine, acupuncture use was associated with a reduced risk of MACE (HR 0.83), and all-cause mortality (HR 0.73). There was also a reduced risk of MI in the PSM, but not of stroke. Having said that, the mortality for all the different cardiovascular disease categories was lower in the acupuncture cohort (HR ~0.70).
More and more of these studies are demonstrating hitherto unexpected (at least by me) benefits associated with acupuncture treatment. I am starting to imagine a future where we all start having regular visits to our acupuncturist once we turn 40. I have always considered myself to be rather unresponsive to the effects of acupuncture, but the more of these large retrospective cohort studies I see, the more I consider booking in for some regular treatment.
1 Jung H, Yeo S, Lim S. Effects of acupuncture on cardiovascular risks in patients with hypertension: a Korean cohort study. Acupunct Med Published Online First: 20 June 2020. doi:10.1177/0964528420920290
2 Zhang J, Lyu T, Yang Y, et al. Acupuncture at LR3 and KI3 shows a control effect on essential hypertension and targeted action on cerebral regions related to blood pressure regulation: a resting state functional magnetic resonance imaging study. Acupunct Med Published Online First: 12 June 2020. doi:10.1177/0964528420920282