Conference News Roundup—American College of Cardiology
Zika Virus May Harm the Heart
As the Zika virus continues to spread globally, new evidence has emerged about the virus’s potentially detrimental effects on the heart, according to the first study to report Zika-related heart troubles following infection. The investigation included adult patients with no prior history of cardiovascular disease who were treated at the Institute of Tropical Medicine in Caracas, Venezuela, one of the epicenters of the Zika virus outbreak. All but one patient developed a dangerous heart rhythm problem, and two-thirds had evidence of heart failure.
“Our report provides clear evidence that there is a relationship between the Zika virus infection and cardiovascular complications,” said Karina Gonzalez Carta, MD, a cardiologist and research fellow at the department of cardiovascular diseases at Mayo Clinic in Rochester, Minnesota, and the study’s lead author. “Based on these initial results, people need to be aware that if they travel to or live in a place with known Zika virus and develop a rash, fever, or conjunctivitis, and within a short timeframe also feel other symptoms such as fatigue, shortness of breath, or their heart skipping beats, they should see their doctor.”
Dr. Carta and her team were not entirely surprised by their findings, as they follow trends seen with other mosquito-borne diseases known to affect the heart, including the dengue and Chikungunya viruses. However, she noted that the burden and severity of heart problems, including rapidly progressive heart failure and potentially life-threatening arrhythmias, among these patients was unexpected.
Nine patients who were seen in the clinic in Caracas within one week of having Zika-type symptoms and who subsequently reported common symptoms of heart problems, most commonly palpitations followed by shortness of breath and fatigue, were included in this small, prospective case report. One patient had previous cardiovascular problems (ie, well-controlled high blood pressure), and laboratory tests confirmed that all had active Zika infection. Patients were asked to fill out a form to record their symptoms and underwent an initial ECG. These findings prompted researchers to perform a full cardiovascular work up using an echocardiogram, 24-hour Holter monitor, and a cardiac MRI study. Of the nine patients, six were female, with a mean age of 47. They were followed for an average of six months, beginning in July 2016.
Dangerous arrhythmias were detected in eight of the nine patients: three cases of atrial fibrillation, two cases of nonsustained atrial tachycardia, and two cases of ventricular arrhythmias, which can be deadly. Heart failure was present in six cases. Of these, five patients had heart failure with low ejection fraction, and one had heart failure with preserved ejection fraction along with pre-eclampsia and a moderate to severe amount of pericardial effusion. So far, none of the patients’ cardiac issues have resolved, though symptoms are much improved due to guideline-directed treatment for heart failure or atrial fibrillation. Cardiovascular symptoms tend to manifest later in the process. Data show an average lag of 10 days from patients’ initial complaints of Zika symptoms to reports of symptoms suggestive of heart problems.
“Since the majority of people with Zika virus infections present with mild or nonspecific symptoms, and symptoms of cardiovascular complications may not occur right away, we need to raise awareness about the possible association,” Dr. Carta said.
Serum Ceramide Levels Predict Cardiovascular Events
Measuring concentrations of a class of lipids known as ceramides in the blood may help clinicians identify individuals with suspected coronary heart disease who need treatment or should be followed more closely, according to research. Although previous research conducted outside the US has shown elevated ceramide levels among people with confirmed heart disease or post heart attack, this is the first study to show its predictive power among people with no blockages and in those with low levels of low-density lipoprotein (LDL).
Study data show that ceramides were able to predict major cardiovascular events (ie, heart attack, stroke, revascularization, and death) among patients with and without evidence of blockages and in those with low LDL. In fact, individuals with the highest levels of blood ceramides had a threefold to fourfold greater risk of having a cardiovascular event, compared with those with the lowest ceramide score, regardless of their LDL cholesterol level or the presence of a blockage in the heart’s arteries.
“Based on our findings, measuring ceramides in the blood appears to be a new, potentially better marker than LDL in predicting first and repeat cardiac events in both patients with and without established coronary blockages,” said Jeff Meeusen, PhD, a clinical chemist and codirector of Cardiovascular Laboratory Medicine at Mayo Clinic in Rochester, Minnesota, and the study’s lead author. “Heart disease remains the number one killer in the United States. Measuring ceramides offers another piece of information to help identify individuals who might need a little more attention, guide treatment decisions, and keep patients motivated to [live heart healthier].”
Unlike cholesterol, which is fairly inert, acting like a clog in the arteries, ceramides play an active role in the cardiovascular disease process by attracting and drawing inflammatory cells and promoting clotting. All cells have the ability to make ceramides; however, ceramide levels tend to accumulate in the blood when one has too much fat or consumes excess calories.
The study included 499 patients at Mayo Clinic who were referred for coronary angiography to check for possible blockages in the heart’s arteries. About 46% of participants had evidence of a blockage. Coronary artery disease was defined as 50% stenosis in one or more artery. Patients were similar in age and with regard to blood pressure, smoking status, and high-density lipoprotein (HDL). Those who had diabetes or a previous heart attack, stroke, or procedure to open narrowed coronary arteries were excluded. Researchers measured four types of ceramides in the blood at baseline and combined the values into a 12-point scale. Patients were grouped into the following four risk categories according to their ceramide levels: low (0–2), intermediate (3–6), moderate (7–9), and high (10–12).
Researchers prospectively followed study participants for an average of eight years and recorded occurrences of heart attack, stroke, revascularization, and death. Overall, 5.1% of patients had a major cardiovascular event during the study. The risk of having an event increased as the level of ceramides in the blood increased; for each one-point increase in the ceramide risk score, the risk rose by 9%—a trend that remained even after fully adjusting for other risk factors, including age, sex, high blood pressure, smoking, total cholesterol, HDL, and markers of inflammation. In fact, the rate of events was double among people with the highest ceramide score, compared with those with the lowest (8.1% vs 4.1%). Total cholesterol also increased with rising ceramide scores, and males were less likely to have high levels of ceramides.
Among those without coronary artery disease upon angiography, the rate of cardiovascular events was 3.1%, which was lower than the average. But when researchers examined cardiovascular disease in this population by ceramide scores, people with the highest levels of ceramides were four times more likely to have an event, compared with those with the lowest (7.8% vs 2.2%). A similar trend was seen among people with low LDL levels (<100 mg/dL). In this group, the rate of heart attack, stroke and revascularization, and death was 3.7% among those with a low ceramide score, but increased to 16.4% in people with the highest ceramide levels.
“Ceramides continued to be significant and independently associated with disease even after adjusting for traditional and novel cardiovascular risk factors,” said Dr. Meeusen. “[Based on what we are seeing,] ceramides appear to be much more important than previously recognized.”
