AHA: Heart disease remains leading cause of death worldwide; trends discouraging
Heart disease remains the leading cause of death globally, according to the annual heart disease and strokes statistics update from the American Heart Association.
In 2019, the latest year for which statistics were available, nearly 18.6 million people worldwide died from CVD, an increase of 17.1% in the past decade, according to the update.
In addition, 523.2 million people had CVD in 2019, up 26.6% from 2010, the researchers wrote.
Published in Circulation, the 2021 statistical update overviews decades of population research in CV events and mortality, and includes information on prevalence of specific CVDs, risk factors and identifies at-risk subgroups.
Although the report compiles statistics from before the COVID-19 pandemic, the researchers said they believe the pandemic will make the CVD numbers worse in the coming years.
“COVID-19 has taken such a huge toll on human life worldwide and is on track to become one of the top three to five causes of death in 2020. But its influence will directly and indirectly impact rates of cardiovascular disease prevalence and death for years to come,” Salim S. Virani, MD, MPH, FAHA, professor of medicine and cardiology at Baylor College of Medicine, staff cardiologist at the Michael E. DeBakey VA Medical Center in Houston, Texas, and chair of the update’s writing committee, said in a press release. “Research is showing that the unique coronavirus can cause damage to the heart. Importantly, we also know people have delayed getting care for heart attacks and strokes, which can result in poorer outcomes.”
Most prevalent risk factors
Poor lifestyle behaviors contribute greatly to the prevalence of CVD, and these too may be exacerbated by the pandemic, Virani said in the release.
High BMI, fasting plasma glucose and smoking are the three leading risk factors contributing to years lived with disability and injury in the U.S. for both 1990 and 2019; smoking and high systolic BP remained first and second in risk factors contributing to years of life lost during that time; and, globally, high fasting plasma glucose and BMI were the first and second leading risk factors contributing to years lived with disability and injury in 2019.
According to the National Health and Nutrition Examination Survey 2015-2018, among U.S. adults aged at least 20 years, the adjusted prevalence of obesity was 39.9% among men and 41.1% among women; extreme obesity was prevalent among 6.2% of men and 10.5% of women; and the overall prevalence of obesity among youth aged 2 to 19 years was 19%.
In the U.S., tobacco use was the second leading cause of disability-adjusted life-years in 2016, the committee wrote.
There was a sharp increase in e-cigarette use among adolescents in the past 8 years, increasing from 1.5% in 2011 to 27.4% in 2019. According to the update, e-cigarettes are now the most-used tobacco product among adolescents.
Prevalence of high BP and CVD
Using NHANES data from 1999-2002, 2007-2010 and 2015-2018, the committee observed an approximately 10% increase in hypertension awareness, treatment and control within each race/ethnicity and sex subgroup, except for Black women.
Among Black women, hypertension awareness, treatment and control increased from 1999-2002 to 2007-2010 but decreased from 2007-2010 to 2015-2018, according to the update.
“We know that in Black patients, men or women, high BP is a very malignant disorder. It is much more difficult to control, possibly related to genetic causes as well as some lifestyle-related causes,” Virani told Healio. “Control has always been an issue. Even if you look at the most recent NHANES data ... the BP control rates are in the 20% to 25% range. BP treatment requires good lifestyle and in a large majority of patients, multiple therapies. We need to, as clinicians, do a better job of communicating this with our patients and that is where you are seeing those differences. Going back to the Black women, what you see here is they had high awareness levels to begin with, but the improvement we have seen in the other groups, that sort of improvement was not seen among Black women.”
The prevalence of elevated BP and hypertension significantly decreased from 16.2% in 2003-2004 to 13.3% in 2015-2016 among children and adolescents aged 8 to 17 years. The prevalence of hypertension alone declined from 6.6% to 4.5% within this age group.
Based on NHANES data from 2015-2018, the prevalence of CVD (CHD, HF, stroke and hypertension) among adults aged at least 20 years was 49.2% overall, or 126.9 million individuals in 2018, and increased with age in both men and women. Excluding hypertension, the overall prevalence of CVD is 9.3%, or 26.1 million individuals in 2018.
According to a county-level analysis, stroke mortality among U.S. adults aged 35 to 64 years increased from 14.7 per 100,000 in 2010 to 15.4 per 100,000 in 2016. Stroke mortality decreased among adults aged at least 65 years from 299.3 per 100,000 in 2010 to 271.4 per 100,000 in 2016, the committee wrote.
Awareness of stroke symptoms and signs improved from 2009 to 2014: In 2014, 68.3% of the National Health Interview Survey respondents were able to recognize five common stroke symptoms and 66.2% demonstrated knowledge of all five stroke symptoms and the importance of calling emergency services.
According to the update, the prevalence of atrial fibrillation in the U.S. was estimated at 5.2 million in 2010 and was projected to increase to 12.1 million by 2030.
Moreover, hypertension was found to be the most common comorbidity associated with AF, observed in approximately 22% of those with AF, followed by obesity, smoking, cardiac disease and diabetes.
In addition, HF was prevalent in an estimated 6 million U.S adults aged at least 20 years, according to 2015-2018 data. The prevalence of HF was higher among women compared with men aged at least 80 years, and the overall prevalence was particularly high among Black individuals.
The prevalence of valvular disease was found to be 64 per 100,000 person-years, with aortic stenosis accounting for 47.2% of cases, mitral regurgitation accounting for 24.2% and aortic regurgitation accounting for 18%.
Trends in adverse pregnancy outcomes
“This was the first year that we have actually described these statistics. The reason for this is that now there are numerous studies showing that adverse pregnancy outcomes are associated with future increased risk of CVD in the mother and in the offspring,” Virani said in an interview. “We've talked about hypertensive disorders of pregnancy, gestational diabetes, small-for-gestational-age babies and preterm birth and what we know is that the prevalence is somewhere between 10% to 20% of pregnancies. Some — for example, gestational hypertension — may be especially relevant to ethnic minorities. Making sure that those women who are diagnosed with these disorders maintain a healthy lifestyle, have regular follow-up with their obstetrician, primary care clinician and, in some cases, specialists, and to understand that they are at a higher risk, and close follow-up is important.”
Using data from the National Hospital Discharge Survey, chronic hypertension in pregnancy, defined as systolic BP of at least 140 mm Hg or diastolic BP of at least 90 mm Hg before pregnancy or up to the first 20 weeks during pregnancy, increased more than 13-fold from 1970 to 2010, according to the update.
Moreover, Black women experienced a twofold greater incidence of chronic hypertension compared with white women during that time.
A meta-analysis of individual participant data from 265,270 women from 39 European, North American and Oceanic cohorts showed that risk for adverse pregnancy outcomes was greater among higher levels of prepregnancy BMI and greater degree of gestational weight gain (adjusted OR = 2.51).
Another meta-analysis that evaluated CV outcomes associated with gestational hypertension described a 67% increased risk for subsequent CVD. The same analysis also found that incidence of preeclampsia was associated with a 75% higher risk for subsequent CVD mortality.
Moreover, based on data from the Swedish Birth Registry from 1973 to 1994 followed up through 2015, gestational age at birth was inversely associated with risk for premature CHD compared with those born full term (aHR for preterm = 1.53; aHR for early term = 1.19).
“A lot of these disorders — for example, gestational hypertension and gestational diabetes — have intermediate phenotypes such as development of BP a few years down the line or development of diabetes a few years down the line,” Virani told Healio. “Very close follow-up and screening for these intermediate phenotypes is important. Lifestyle therapy-related discussions with women who have these disorders are especially important because if a woman improves her diet and increases her physical activity, her child that's born is also more likely to be doing that too. This is a two-for-one. We can make a large impact in the overall population by focusing on the mother here.”