VOLUME 19 NUMBER 1 • July 2022 19 SA JOURNAL OF DIABETES & VASCULAR DISEASE DIABETES NEWS cardiomyopathy and heart failure, and deprive people of their mobility and independence. But a small study, published in the New England Journal of Medicine, offers hope that a therapeutic agent based on the advanced gene editing technology CRISPR-Cas9 (recently recognised with a Nobel prize) may change the course of the disease. Scientists targeted the gene defect responsible for the faulty TTR protein in six volunteers with hereditary transthyretin amyloidosis. Four weeks after the therapy was infused, concentrations of the aberrant protein in patients’ blood fell on average 52% with a lower treatment dose and 87% with a higher dose. Other research explored potential benefits of a CRISPR-Cas9-based therapy in Duchenne muscular dystrophy, which affects one in about 5 000 boys. The disease causes severe muscle wasting and weakness, as well as cardiomyopathy and breathing complications that are common causes of death. In a series of experiments described in the AHA journal Circulation Research, Dallas scientists examined whether gene editing might help protect patients’ hearts. The team created induced pluripotent stem cells, a type of reprogrammed cell that can grow into different adult cell types, from a patient with Duchenne muscular dystrophy and from a healthy brother. Gene editing allowed the patient’s cells to become heart muscle cells that looked and functioned like those from the healthy brother. And in a scenario closer to how the disease appears in patients, cells that were edited later (once they became heart muscle cells) had less potential for arrhythmia, the team reported. Also, applying their gene-editing approach to a mouse model of Duchenne muscular dystrophy, the scientists showed that edited cells might improve heart abnormalities. Findings highlight simple successes in blood pressure control, from kitchen table to clinic There’s no substitute for good cardiovascular health. But substitution might help, by replacing 25% of the sodium chloride in your salt shaker with potassium chloride instead. The massive Salt Substitute and Stroke Study from China, involving 600 rural villages and nearly 21 000 people, documents the benefits in a population where eating processed food is uncommon but salt intake is high. Participants either had a history of stroke or were 60 years or older with poorly controlled high blood pressure. With an average follow up of nearly five years, rates of stroke were 14% lower in villages assigned to use the salt mixture containing25%potassiumchloride, compared with those where regular (all-sodium chloride) salt use continued, researchers wrote in the New England Journal of Medicine. Observers, however, note that elsewhere in the world, commercial food preparation, rather than salt added at home, is a major source of dietary sodium chloride. Another large trial from China, dubbed STEP, which focused on people aged 60 to 80 years, sheds new light on potential benefits of tighter blood pressure control. That trial enrolled more than 8 500 people with hypertension (defined as a systolic blood pressure of 140 to 190 mmHg or taking antihypertensive medication). Those with a history of stroke were excluded. Half were assigned to intensive treatment, with a target for systolic blood pressure of 110 to less than 130 mmHg. The systolic target for the rest was 130 to less than 150 mmHg. Over more than three years of follow up, researchers tracked whether participants died of cardiovascular disease or had a stroke, heart attack, heart failure or various other heart problems. Those outcomes occurred in just 3.5% of people with the intensive-treatment goal, scientists reported in the New England Journal of Medicine, compared with 4.6% in the other group. The findings support current AHA and American College of Cardiology guidelines for managing high blood pressure, which set a systolic goal of less than 130 mmHg for most patients. COVID-19 puts young people’s heart health in the headlines For children and young adults, the pandemic has posed special challenges in the form of rare but serious conditions linked to the virus or to two of the vaccines. Experts have acted quickly to characterise those conditions. In the journal Circulation, European investigators presented a heart-focused snapshot of a newly emerging, coronavirus-related condition, multisystem inflammatory syndrome in children (MIS-C). MIS-C can cause dangerous inflammation in the heart, lungs, kidneys, brain, skin, eyes and other organs. The study, involving 286 young patients with MIS-C from across Europe, captured the new syndrome’s most common cardiac implications: arrhythmias, shock, reduced ejection fraction, dilated coronary arteries and fluid build-up in the pericardial sac around the heart. Inflammatory markers were raised in most of the children, the scientists noted. And nearly two-thirds had evidence of previous infection with the virus that causes COVID-19. Other research sought to better understand cases of myocarditis, or heart muscle inflammation, arising after vaccination with either of the new mRNA vaccines, from PfizerBioNTech or Moderna. Leveraging nationwide data in the wake of a brisk immunisation campaign in Israel, one massive study found only 136 definite or probable myocarditis cases, one fatal, among more than five million people aged 16 years and older who were given the Pfizer vaccination from December 2020 until May 2021. Risk was highest within a week after the second dose in the two-shot series. In all, almost four in 100 000 boys or men, and fewer than one in 100 000 girls or women, developed myocarditis within 30 days after their second Pfizer dose, the researchers calculated. But those odds were almost 11 in 100 000 in men aged 20 to 24 years and 15 in 100 000 among males aged 16 to 19 years, the group with the highest rate. The other study, of 2.5 million patients at a major healthcare provider and insurer in Israel, pinpointed 54 myocarditis cases in a five-month window and highlighted medical details of the cases. Overall, the risk of myocarditis after vaccination was low, the studies concluded. Most cases were mild or moderate and eventually resolved. Both studies were published in the New England Journal of Medicine. The AHA continues to recommend vaccination against COVID-19 in adults and eligible children and notes that ongoing research clearly shows a far greater risk of heart complications, stroke and blood-clotting problems after COVID-19 infection than after vaccination. Fighting the flu heads off cardiovascular and other risks too Vaccinating people against flu within 72 hours of a heart attack or invasive coronary procedure may yield health benefits beyond the flu season, research published in Circulation found. An international team of investigators gave 1 272 heart patients a flu shot and 1 260 a saline placebo, then tracked their health for a year. Compared with the placebo group, those who were vaccinated were 28% less likely to have a heart attack or a dangerous clot in a coronary stent or die of any cause, the study found. They also were 41% less likely to die of cardiovascular disease. Stroke advances address the need for speed As the saying goes, time is brain: fast treatment that removes a blockage and restores blood flow can minimise the damage stroke inflicts. Two studies in 2021 examined efforts to shave minutes off the time from stroke onset to initiation of therapy. Both reported better patient outcomes.
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