Heart-Failure Burden in Asia Linked to Modifiable Factors

Liam Davenport

July 25, 2017

SINGAPORE — Heart-failure patients in Asia are generally younger but have a higher comorbidity and risk-factor burden than those in other parts of the world and are more likely to have heart failure with preserved ejection fraction (HFpEF), shows a new heart-failure registry that also revealed health inequalities across the region[1].

The registry of more than 5000 patients in 11 countries, presented at the 21st Asian Pacific Society of Cardiology Congress, showed that both HFpEF patients and heart-failure patients with reduced ejection fraction (HFrEF) had, despite a young average age, a high comorbidity rate, particularly among women.

Lead researcher Dr Carolyn Lam (National Heart Center, Singapore, and Duke-National University of Singapore) speculated to theheart.org | Medscape Cardiology that this may be due the rapid pace of economic development in Asia.

"In general, the burden of cardiovascular disease has really shifted to Asia, if you take a global view of things," she said, adding that the highest risk-factor burden for heart failure "was in countries that had the most rapid epidemiologic transition over recent years."

She used Singapore as an example. "It's only a 50-year-old nation; in other words, 50 years ago it was fishing village, and now it's a metropolis. I think it's that rapid transition, rapid wealth, that has all the trappings of diabetes, hypertension, and so on coming in as we rapidly took on the Western lifestyle," Lam said.

Furthermore, the research showed that there was a wide variation in combined mortality and heart-failure hospitalization, with the highest rates seen in Southeast Asia.

The registry also revealed that there was a huge range in the utilization of implantable cardiac defibrillators (ICDs) across the region, with less than 2% of eligible patients receiving the potentially lifesaving devices in Indonesia, for example.

To tackle such health inequalities, Lam believes that it "begins with awareness," noting: "Some countries still track heart failure as a consequence of other diseases like coronary artery disease, so we're not even tracking heart failure."

She added: "There's huge areas where heart failure is just not taken seriously because they don't know what it is. They just think it's a bit of breathlessness and so on."

President of the European Society of Cardiology, Dr Jeroen J Bax (Leiden University Medical Center, the Netherlands). was the study discussant in Singapore.

In an interview, Bax said that, in Western Europe and the US, "what we see most is heart failure with reduced ejection fraction, and this mostly related to coronary artery disease, whereas in Asia, they see relatively more heart failure with preserved ejection fraction, much more than we see in Europe."

Bax said that HFpEF is primarily associated with risk factors such as hypertension, diabetes, and atrial fibrillation, alongside female gender and age, and that the high rate of HFpEF in Southeast Asia in particular was related to the very high rates of these modifiable risk factors in that region.

Underlining the need to recognize that, in Asia, heart failure is related to different risk factors from those in Europe or the US, he said that the treatment of heart failure with preserved ejection fraction "is difficult at the moment."

"It's different in pathophysiology from reduced ejection fraction HF, which is mostly a systolic-pump–function problem, whereas in this case it's more like a relaxation problem, mostly a diastolic relaxation problem," he added. "We have no really good medications for that, so that means we need to focus on treating the risk factors."

It's important, Bax said, to understand better why diabetes, hypertension, and atrial fibrillation are so prevalent in these countries, "so that we can strive for prevention of the development of these risk factors, and that will then result in preventing heart failure with preserved ejection fraction."

While it is known that Asia has the highest burden of hypertension and diabetes in the world, there are few data on the characteristics and outcomes of HFrEF, defined as an ejection fraction <40%, or HFpEF (ejection fraction ≥50%) across the region.

To investigate further and to examine the utilization of ICDs in Asian HF patients, the researchers established the Asian Sudden Cardiac Death in Heart Failure (ASIAN-HF) registry, which gathered data on 5276 HFrEF and 1203 HFpEF patients from 11 Asian countries.

These were grouped as East Asia (Hong Kong, Taiwan, China, Japan, and Korea, n=543), South Asia (India, n=252) and Southeast Asia (Malaysia, Thailand, Singapore, Indonesia, Philippines, n=408).

The researchers defined patients as being eligible for an ICD if they had an ejection fraction ≤35% and NYHA class 2–3 heart failure.

The average age of HFrEF patients was 59.6 years, and 78.2% were men. The average body-mass index (BMI) was 24.9 kg/m2. Among HFpEF patients, the mean age was 68 years and 50% were women, while the mean BMI was 27.0 kg/m2.

These figures suggested that Asian HF patients are younger on average than their US counterparts, where the mean age for HFrEF patients is 70 years and that for HFpEF patients is 72 years.

Moreover, the results showed that two-thirds of patients had at least two comorbidities, with the burden highest in Southeast Asia.

The team found that having at least two comorbidities increased the likelihood of having HFpEF vs HFrEF approximately twofold, while being a woman increased the odds threefold. In contrast, the presence of HFrEF vs HFpEF was associated with coronary artery disease, chronic kidney disease, and left bundle branch block.

The results also showed that, at 6 months, 13.9% of HFrEF and 8.6% of HFpEF patients had died or were hospitalized for HF, with the highest rates seen in Southeast Asia, at 19.4% and 15.2%, respectively.

Of 3240 patients who were eligible to receive an ICD, 389 (12%) received them, with utilization among eligible patients ranging from 1.5% in Indonesia to 52.5% in Japan.

Analysis revealed that ICD recipients were significantly more likely to be older than nonrecipients, at 63 years vs 58 years (P<0.001). They were also significantly more likely to have tertiary-level education, at 34.9% vs 18.1% for primary education (P<0.001), and be living in a high-income region, at 64.5% vs 36.5% for a low-income region (P<0.001).

ICD implantation was found, over a median follow-up of 417 days, to be associated with a reduced risk of all-cause mortality (hazard ratio 0.71, 95% CI 0.52–0.97) and sudden cardiac death (hazard ratio 0.33, 95% CI 0.14–0.79).

Next, Lam and colleagues will examine the utilization of guideline-directed medical therapies in Asia and are completing follow-up in a cohort of HFpEF patients.

"Then there are lots of things that we're looking at, including looking in greater detail at the role of diabetes in all of this, and we want to look at medical therapy the same way we looked at device therapy, just to name a few," she said.

Lam and colleagues and Bax had no relevant financial relationships.

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