Heart failure in Asia: the present reality and future challenges

Abstract

In Asia, rapid economic growth has increased cardiovascular risk factors—obesity, diabetes mellitus, and hyperlipidaemia. This is due to hectic urban lifestyles' common companions—poverty of physical activity, tobacco smoking, and diets rich in calories, salt, and cholesterol. These unhealthy lifestyles commonly lead to cardiovascular diseases such as coronary artery disease (CAD) and hypertension, which in turn lead to the common path of heart failure (HF).

Present reality

Heart failure is a global problem, including Asia. The estimated prevalence of HF in India is 1.3–4.6 million with an annual incidence of 0.5–1.8 million.¹ Jiang and Ge² reported that in China, the HF prevalence rate among the general population was 0.9%. In that study, it was highlighted that in contrast to the West, the prevalence of HF in China was lower than in Western countries, but there was a higher prevalence of females with chronic HF. While common causes such as CAD and hypertension were similar to the Western world, other common HF aetiologies in China included rheumatic valve disease, cardiomyopathy, tuberculosis pericarditis, and pulmonary heart disease, in contrast to the West. That study also revealed that with rapid globalization, social economic development, and urbanization from 1980s, the now prosperous and urban Shanghai and the Western HF epidemiology profiles were converging, with CAD being the most common HF aetiology. Heart failure has significant mortality, readmissions morbidity, and high health costs. In Singapore, our national HF registry revealed that there were 4530 admissions into our six public hospitals for HF in 2009, a rise of 9.4% from 2008, when there were 4140 admissions (unpublished data). With ageing populations, changing disease epidemiology profiles, and improved management of HF itself, HF disease burden in Asia will grow.

Heart failure management strategies have for a long time been restricted to bed rest, supplemented with digoxin and diuretics. This remained unchanged till 1986. In that year, the pharmacological therapeutic era for HF was re-born with isosorbide and hydralazine vasodilator therapy. Cohn et al. showed that this combination significantly reduced mortality and improve left ventricular ejection fraction.³ This has since been followed by the race for complete inhibition of the sympathetic and renal–angiotensin–aldosterone systems, with the successful development of angiotensin-converting enzyme inhibitors, β-blockers, aldosterone receptor blockers, and aldosterone antagonists. These medications are now standard therapies in HF.⁴ These medications are available in Asia, many of them in more affordable generic formulations. However, their use is still limited.² As for bed rest in HF, physical activity is now recommended to improve a sense of well-being while evidence on readmissions and mortality benefits are still equivocal.⁴ There is much research on this in Hong Kong; however, the adoption of comprehensive cardiac rehabilitation programmes are still limited outside the West.⁵

Numerous studies, much of it done in Hong Kong, have shown that ICD, then CRT-D, improved outcomes in appropriately selected patients with systolic HF⁶ and is now recommended as therapy in the ESC and ACC HF guidelines. Other devices now recommended in the ESC and ACC HF guidelines⁷ include ventricular assist devices (VAD), whose technology has improved, and their size shrunk, to manage advanced systolic HF, and ultrafiltration, a novel mechanical form of diuresis introduced in the treatment of diuretic resistant congested HF. In Asia, these devices are available at the major population centres. In Singapore, the Health Ministry subsidizes the implantation of ICD and CRT-D devices and VAD in appropriately qualified patients. Ultrafiltration was introduced in Singapore this year. Heart transplant, the definitive therapy for end-stage HF, is available in Asia, including Singapore. However, its use is limited. Asia has 60% of the world's population, but accounts for only 4% of heart transplantations performed. In comparison, North America has 5% of the world's population, but 71% of heart transplantations performed.⁸

Multidisciplinary disease management programmes do reduce HF readmissions and improve quality of life and are recommended in the ESC and ACC HF guidelines.^4,7 There are such multidisciplinary HF programmes in the major public hospitals in Singapore.

Let us not forget diastolic HF, the commonly misunderstood cousin of systolic HF. In the past two decades, we have come to know it better, reaching a consensus on its definition, and recommendations for its therapy.⁹ However, we still wait for strong evidence for mortality reducing therapeutics in diastolic HF.

Future challenges

Looking ahead, we wait for stronger evidence for novel medications in HF. Tolvaptan, an oral, non-peptide vasopressin V2-receptor antagonist, is one such drug. It has been shown to be a safe diuretic in HF patients with hyponatraemia. A study in Japan is ongoing to assess its prognostic effect in HF. We are also using older drugs with novel indications in HF. One such drug is sildenafil. The ongoing Evaluating the Effectiveness of Sildenafil at Improving Health Outcomes and Exercise Ability in People With Diastolic Heart Failure (RELAX) study will assess its use in diastolic HF.

Renal denervation is a novel percutaneous electrical sympathectomy used to treat resistant hypertension.¹⁰ Its efficacy in HF management is being assessed in the SYMPLICITY HF study in Australia, as sympathetic nervous system modulation has been a major goal in HF therapy.

As for devices, following the development history of conventional pacemakers, we can expect them to be smaller, more resilient, and easier to implant.

In Asia, we need to prepare for the increase in HF burden. The most cost-efficient means will be primary prevention by public education, further restrictions on smoking, and even public health measures to increase physical activity and reduce salt and simple sugars in our diet. We need to increase implementation of proven therapeutic strategies for HF. This mandates greater investments in health-care staff training and infrastructure development. Many of these strategies, especially the devices, are expensive. They require wisdom in public health policies and sustainable funding systems to pay for it.

Conflict of interest: none declared.

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