Higher Risk of Seniors Dying Due to Heart Cell Damage after Non-heart Surgery

Surgery that doesn’t involve the heart may cause damage to the heart in people with known or at high risk of developing heart disease and was associated with an increased risk of death, according to new research in the American Heart Association’s journal Circulation.

Heart cell damage during or after non-heart surgery, known as perioperative myocardial injury (PMI), is an important yet often undetected complication following non-heart surgery and is strongly associated with death within 30 days after surgery, according to research published in the American Heart Association’s journal Circulation. The causes of PMI are still under investigation.

“Patients with PMI are easily missed because they show no symptoms of heart disease in the majority of cases and only very rarely experience chest pain, which is the typical symptom of heart attack,” said Christian Puelacher, M.D., Ph.D., first author of the study and a clinical researcher at Cardiovascular Research Institute Basel, in Basel, Switzerland.

To determine whether a patient’s non-heart surgery damaged heart cells, researchers screened patients for PMI by measuring levels of troponin – a heart protein — in the blood before and after surgery to determine if there was injury to the heart. Troponin can indicate damage to the heart even when the patient has no symptoms. Non-heart surgeries ranged from low-risk (prostate or knee surgery) to moderate risk (hip replacement or gall bladder removal) to high risk (peripheral artery bypass or resection of a lung or the liver).

The researchers found that 1 out of 7 patients above the age of 65 or with preexisting coronary artery disease, peripheral artery disease, or stroke developed PMI. More than 90 percent of PMI patients reported typical chest pain. Patients with PMI had six times more likely to die of any cause within 30 days compared to patients without PMI. The high death rate associated with PMI persisted up to one year after surgery.

The increased death rate within the first 30 days of surgery highlights that PMI is associated with death early after surgery, Puelacher said. After one year, it was clear that the patients who had high levels of troponin, meaning there was some damage to the heart from non-heart surgery, were more likely to die, and that the main increase in deaths was observed within the first weeks after surgery.

“Recognizing PMI as a potential contributor to death after surgery might help improve the outcomes of non-cardiac surgery,” Puelacher said. “However, since there are no clear treatment recommendations for these patients, treatment currently has to be tailored to each patient individually. Therefore, further research is needed to find optimal PMI management strategies following detection.”

Patients were enrolled in the BASEL-PMI study, which is aimed at improving patient outcomes after non-cardiac surgery, focusing on heart complications in the period after surgery. From 2014 to 2015, 2,018 patients with known or at high risk of developing heart disease undergoing 2,546 non-cardiac surgeries at the University Hospital Basel in Switzerland, were included in the study.

Source: American Heart Association


Today’s Comic

Advertisements

Cardiorespiratory Fitness is Essential to Reduce Risk of Coronary Heart Disease


Enlarge image . . . . .

Coronary heart disease (CHD) is a leading cause of death for men in the U.S. Both cardiorespiratory fitness (CRF) and the blood triglyceride/high-density lipoprotein ratio (TG:HDL ratio) are strong predictors of death from CHD. In the current issue of Mayo Clinic Proceedings, two new studies highlight the importance of CRF on subsequent CVD and mortality risk. These articles contribute substantive evidence on the importance of achieving moderate to high levels of CRF in both adults and children.

In an investigation led by Stephen W. Farrell, PhD, of The Cooper Institute, Dallas, TX, researchers found strong evidence that moderate-to-high level of fitness counteracted some of the negative effects of a high TG:HDL ratio.

“While it is still extremely important to measure traditional risk factors such as resting blood pressure, blood cholesterol, triglyceride, and glucose levels, having a measure or estimate of the patient’s cardiorespiratory fitness level gives us additional information regarding cardiovascular disease risk,” explained Dr. Farrell. “The results of this study support this recommendation. Regardless of whether the blood TG:HDL ratio was low or high, having at least a moderate level of fitness provided some protection from CHD death when compared to having a low level of fitness.”

A total of 40,269 men received a comprehensive physical examination between January 1, 1978 and December 31, 2010. The exam included a maximal treadmill exercise test to measure cardiorespiratory fitness level, and also included measurement of the blood TG:HDL ratio. This ratio is easily calculated by taking the fasting blood triglyceride level and dividing it by the blood HDL cholesterol level. A lower ratio is an indicator that insulin is working well, while a higher ratio indicates resistance to insulin. Higher ratios also indicate an increased risk of future prediabetes, type 2 diabetes, and cardiovascular disease.

The participants, categorized into low, moderate, and high CRF groups, were followed for an average period of 16.6 years, during which time 556 deaths due to coronary heart disease (CHD) occurred. Moderate to high levels of fitness provided significant protection from CHD death. Lower values for the TG:HDL ratio also provided significant protection. The lowest risk of CHD death was seen among high fit men in the lowest category of TG:HDL ratio, while the highest risk of CHD death was seen among low fit men in the highest category of TG:HDL ratio. Within each of the four categories of TG:HDL ratio, having a moderate to high level of fitness provided significant protection against CHD death when compared to having a low level of fitness. Therefore, knowing the patient’s fitness level as well as their TG:HDL ratio provides much more information about CHD risk status than just knowing one or the other. When used in combination with other risk factors, such as the patient’s blood pressure, bloodwork, family history, etc., measuring or estimating the patient’s level of CRF can result in a much more accurate determination of their cardiovascular disease risk status.

There are also some studies that indicate that the TG:HDL ratio can be a proxy for LDL particle size, whereby small dense LDL particles are more likely to form plaques in blood vessels than large, less-dense particles.

It has often been said that “Exercise is Medicine.” Many risk factors for chronic disease can be prevented or treated with sufficient amounts of exercise, weight loss, and healthy diet. Avoiding tobacco in all forms is also a must.

In another study researchers from several universities and institutes in Spain highlight the importance of monitoring CRF for early detection of present and future cardiovascular risk in youth. They describe how measuring CRF in 6- to 10-year-olds and later in 8- to 12-year-olds can reveal indicators of increased cardiovascular disease (CVD) risk later in life.

Lead investigator José Castro-Piñero, PhD, from the Department of Physical Education, School of Education, University of Cádiz, Puerto Real, Spain, noted, “Although CVD events occur most frequently during or after the fifth decade of life, there is evidence indicating that CVD precursors have their origin in childhood and adolescence. Moreover, adverse CVD risk factors during childhood have been found to track into adulthood. Consequently, early detection and diagnosis of CVD risk factors in children and adolescents will contribute to the development of effective prevention programs, counseling, school-based strategies, and public health policies.”

Participants were part of the UP&DOWN study of 2225 youths between 6 and 18 years of age, and for this study, 213 primary schoolchildren were tested. CRF was expressed as an oxygen consumption value (units of mL/kg per minute) calculated from a shuttle-run test. Other data collected included skinfold thickness, blood pressure, serum triglyceride (TG) levels, total cholesterol (TC) level, high-density lipoprotein cholesterol (HDL-C) level, glucose level, insulin level, and CRF. From these data, single CVD risk factors were determined as well as an overall CVD risk score.

Researchers determined that several single CVD factors increased during the two-year follow-up period for both boys and girls, while overall CVD risk score increased significantly only for boys. Maximum oxygen consumption decreased for both boys and girls. Boys were about seven times more likely to have a favorable CVD risk score at follow-up if their CRF level was at least 39.0 mL/kg per minute at the beginning of the study. Girls were more than four times as likely to have favorable CVD risk with CRF of at least 37.5 mL/kg per minute at the beginning of the study.

In an accompanying editorial, Carl J. Lavie, MD, of the John Ochsner Heart and Vascular Institute, Ochsner Clinical School-The University of Queensland School of Medicine, New Orleans, LA, observed that collectively the data presented in the study by Farrell et al support significant public health messages. First, CRF significantly modulates CVD risk associated with dyslipidemia. Second, accumulating 7 to 14 miles per week of moderate-intensity exercise, such as running, can potentially lower the risk associated with increased TG:HDL-C levels as reported by the current study. Finally, CRF must be considered by health care professionals when CVD risk is assigned to patients.

Dr. Lavie further stated that by focusing on young children and adding an important longitudinal analysis of how CRF changes relate to changes in CVD risk, Castro-Piñero et al have added two significant dimensions to the existing literature.

Source: EurekAlert!


Today’s Comic

How Big Sugar Killed a 1968 Study That Pointed to Heart Disease Link

Deena Shanker wrote . . . . . .

It’s no secret that big industries have long devoted tremendous resources to shaping scientific debates that may threaten profits, from Big Oil countering how fossil fuels cause climate change to Big Tobacco pushing back on how smoking will kill you.

This corporate stratagem, manifesting itself as subsidized scientists or lobbyists masquerading as researchers, can also lead to unexpected results. So when it comes to sugar and whether the sweet stuff does a lot more than rot your teeth, a discarded 50-year-old research project may have come back to haunt Big Sugar.

An investigation published Tuesday in the journal PLOS Biology reveals internal emails obtained from public libraries that illustrate how, almost 50 years ago, the International Sugar Research Foundation (ISRF) terminated funding for its own study—one that according to PLOS Biology report was on the verge of linking sugar with bladder cancer and coronary heart disease.

“The sugar industry has maintained a very sophisticated program of manipulating scientific discussion around their product to steer discussion away from adverse health effects and to make it as easy as possible for them to continue their position that all calories are equal and there’s nothing particularly bad about sugar,” says Stanton A. Glantz of the University of California, San Francisco, one of the PLOS Biology study’s authors.

In a copy of a statement obtained by Bloomberg News, the Sugar Association—the current lobbying arm for the industry—called the new report “a collection of speculations and assumptions about events that happened nearly five decades ago.” According to its own review, the industry group said in the statement, the study in question ended because it was delayed, over-budget and overlapped with organizational restructuring. The organization didn’t immediately return a request for additional comment.

In 1968, the Sugar Research Foundation, a predecessor to the ISRF, launched “Project 259” to answer questions raised by outside researchers about the role gut bacteria played in how humans digested sugar compared with how they digested starch. Triglycerides that result from the process, in high enough amounts, are a recognized risk factor for heart disease. At the time, evidence was already suggesting the link.

W.F.R. Pover at the University of Birmingham was selected to lead the research with about $29,000—or $187,000 in 2016 dollars—in funding. In September 1969, an internal report at the ISRF noted that rats who were fed sugar had higher levels of a particular enzyme, beta-glucuronidase, in their urine.

This discovery wasn’t central to the purpose of the research, but the study published Tuesday noted the red flag it should have represented at the time: By the late 1960s, other scientific publications had found a positive association between higher levels of urinary beta-glucuronidase and bladder cancer.

By August 1970, Pover told the SRF that he had almost answered the study’s original question. He told the group that his work so far suggested that gut bacteria were, in fact, impacted differently depending on whether the rats consumed starch or sugar, and that this would likely explain the higher triglyceride levels in sugar-eaters. But he needed another 3 months of funding to reach this conclusion more definitively.

The next month, as the Sugar Research Foundation was becoming the International Sugar Research Foundation, Vice President of Research John Hickson described Project 259’s value as “nil,” and funding for the study’s final 12 weeks was cut off. It was never finished and no results were ever published.

Four years later, though, an ISRF report interpreted the near-finished project’s findings, according to the new study: Rats with conventional microbiomes fed a high-sugar diet had elevated serum triglyceride levels, “suggesting the triglycerides were formed from fatty acids produced in the small intestine by the fermentation of sucrose.”

In other words, the ISRF was saying, a high-sugar diet may have impacted the rats microbiomes and raised their triglycerides.

“[The study] would have added to the evidence that sugar was influencing heart disease risk by increasing triglycerides,” says Glantz. “My sense is that this would have represented a substantial contribution at the time. Sugar was saying ‘don’t worry about the sugar-heart disease connections,’ this paper would have said ‘yes, worry.’” The sugar industry has resisted efforts to declare a link between sugar consumption and heart disease.

“It’s just one more piece of information that would have added to the picture that was forming,” said lead author Cristin Kearns. “The angle of the gut bacteria, that thread got lost, and I think it maybe would have gotten a lot more attention.”

The implications of what happened to Project 259 go beyond its particular findings, she said. “The sugar industry probably knows more about the health effects of their products than they’re letting on.”

Source : Bloomberg

An Aging Heart May Weaken Memory

A decline in the pumping ability of an older person’s heart can lower blood flow to their brain’s memory center, new research has found.

The study involved 314 people, who averaged 73 years old and did not have heart failure, stroke or dementia. Nearly 40 percent of them had mild cognitive impairment, which increases the risk for dementia, including Alzheimer’s disease.

All participants underwent tests to determine how much blood their heart pumped relative to their body size. They also had MRI scans to assess blood flow in the brain.

“Our findings show that when the heart does not pump blood as effectively, it may lead to reduced blood flow in the right and left temporal lobes, areas of the brain that process memories,” said study author Angela Jefferson. She directs Vanderbilt University Medical Center’s Memory & Alzheimer’s Center, in Nashville.

“What is surprising is the reduction we observed is comparable to brain blood flow in someone 15 to 20 years older,” she added.

The findings were published online in the journal Neurology.

“Our results suggest mechanisms that regulate blood flow may become more vulnerable as a person ages, even before cognitive impairment sets in,” Jefferson said in a journal news release.

“It is also possible the temporal lobes, where Alzheimer’s disease first begins, may be especially vulnerable due to a less extensive network of sources of blood flow,” she said. “If we can better understand how this process works, we could potentially develop prevention methods or treatments.”

Source: HealthDay


Today’s Comic

Higher Thyroid Hormone Levels Associated with Artery Disease and Death

High and high-normal levels of a thyroid hormone called FT4, were associated with artery disease and death in elderly and middle-aged people, according to new research in Circulation Research, an American Heart Association journal.

Researchers analyzed data from 9,420 participants (average age 65, 57 percent women) in the Rotterdam Study looking at data on two types of hormones: thyroid-stimulating hormone and free thyroxine (known as FT4) and their link to atherosclerosis and death due to coronary heart disease, cerebrovascular disease or other artery-related illness.

FT4 is a hormone produced by the thyroid gland that helps control the rate at which the body uses energy. Atherosclerosis is the process of progressive thickening and hardening of the walls of arteries from fat deposits on their inner lining. Researchers determined asymptomatic atherosclerosis by measuring coronary artery calcification.

After a median follow-up of 8.8 years, researchers noted 612 atherosclerosis-related cardiovascular deaths and 934 first-time atherosclerosis-related cardiovascular events. Increasing FT4 levels were associated with:

  • twice the odds of having high levels of coronary artery calcification scores – which may be an indicator of subclinical atherosclerosis;
  • 87 percent greater risk of suffering an atherosclerosis-related cardiovascular event; and
  • double the risk of atherosclerosis-related cardiovascular death.

“We expected that thyroid function would influence the risk of developing atherosclerosis by affecting cardiovascular risk factors such as blood pressure. However, our results remained very similar after accounting for several cardiovascular risk factors,” said lead study author Arjola Bano, M.D., M.Sc., D.Sc., a researcher in internal medicine and epidemiology at Erasmus University in Rotterdam, the Netherlands. “This suggests that mechanisms other than traditional cardiovascular risk factors may play a role.

“Our findings suggest that thyroid hormone FT4 measurement can help identify individuals at increased risk of atherosclerosis.”

The study is believed to be the first population-based study investigating the relationship of thyroid function with atherosclerosis from subclinical atherosclerosis to overt disease and death.

Authors note that the study did not measure thyroid hormone levels over time and included mostly white middle-age adults so the results may not be generalized to other populations.

“Future studies should clarify the exact mechanisms that can explain the link between thyroid function and atherosclerosis. This could help to identify potential targets for future preventative strategies,” Bano said.

Source: American Heart Association


Today’s Comic