Study Reveals Dual-Drug Therapy Significantly Improves Hypertension Management in India

The management of hypertension in India is set to see a major transformation, as findings from a landmark clinical trial have shown that two-drug combinations are significantly more effective than single-drug treatments. The study, conducted by the Centre for Chronic Disease Control (CCDC) in collaboration with the World Health Organisation (WHO) and the Indian Council of Medical Research (ICMR), was led by the All India Institute of Medical Sciences (AIIMS), Delhi.

Known as the TOPSPIN trial, the research involved 35 hospitals across India, including both public and private institutions. Sponsored by Imperial College, London, the trial evaluated the efficacy of three specific drug combinations: amlodipine with perindopril, amlodipine with indapamide, and perindopril with indapamide. It was found that approximately 70% of patients achieved blood pressure (BP) control using these combinations—making the approach five times more effective than monotherapy.

The results, presented at the 2024 scientific sessions of the American Heart Association in Chicago, highlighted that all three combinations performed equally well in reducing both ambulatory BP (monitored over 24 hours) and office BP (measured during doctor visits). The medications tested are already available in India under popular brand names, making them accessible for widespread use.

Hypertension, or high BP, is diagnosed when pressure in the blood vessels exceeds 140/90 mm Hg. This condition, affecting nearly 30% of India’s population, is a leading cause of mortality and disability. Unfortunately, the rates of effective BP control remain alarmingly low, with only 11% in rural and 20% in urban areas achieving the desired targets, as reported by ICMR.

Importance of Combination Therapy

The trial addressed a significant gap in hypertension management guidelines in India, which have largely been based on international data. Experts have long emphasized that lowering BP to target levels is critical for preventing cardiovascular complications. However, existing guidelines lacked specific data on the most effective drug combinations for South Asians.

The TOPSPIN trial enrolled 1,981 patients aged 30 to 79 years, with a median age of 52, between 2022 and 2024. Participants were randomly assigned to receive one of the three drug combinations in a single-pill format. At the start of the trial, over half the participants were already on some form of BP medication, while 18.6% had type 2 diabetes, and 6.2% were smokers.

Over six months, ambulatory BP levels dropped by 14/8 mm Hg on average, while office BP levels showed an even more pronounced reduction of 30/14 mm Hg. The study achieved BP control in nearly 70% of participants, with 40% reaching the stricter target of 130/80 mm Hg.

Safety and Additional Benefits

The safety profile of all three drug combinations was deemed excellent, with fewer than 3% of participants discontinuing treatment due to side effects. Notably, patients in the amlodipine-perindopril group also experienced a reduction in fasting blood sugar levels, adding a metabolic benefit to the regimen.

Dr. Ambuj Roy, a cardiology professor at AIIMS and one of the study’s principal investigators, emphasized that the trial provides much-needed evidence to guide treatment choices for South Asians. He pointed out that while these combinations are already prescribed, this study offers scientific validation tailored to the Indian population.

Hypertension in India: A Public Health Challenge

The WHO’s 2023 Global Report on Hypertension revealed that over 188 million Indians aged 30-79 years are affected by high BP. Despite this, only 37% are diagnosed in time, and merely 30% receive treatment. Current guidelines recommend initiating combination therapy for most adults, particularly those with comorbidities, as monotherapy is often insufficient to achieve optimal BP control.

Combination therapies typically include:

• ACE inhibitors like perindopril, which relax blood vessels.

• Calcium channel blockers (CCBs) like amlodipine, which prevent calcium from entering heart and blood vessel cells, promoting relaxation.

• Thiazide or thiazide-like diuretics like indapamide, which reduce fluid retention by increasing salt and water excretion.

While these combinations are endorsed in Indian hypertension guidelines, the TOPSPIN trial is the first to specifically evaluate their effectiveness in South Asian populations.

Global Implications and Ethnic Differences

Interestingly, the study found no significant differences in BP control among the three combinations, a result that contrasts with findings from the CREOLE study conducted in Sub-Saharan Africa. This suggests that the effectiveness of combination therapies may vary across ethnic groups.

Dr. Neil Poulter, a professor at Imperial College, highlighted the broader implications of the findings, stating that they will help shape hypertension management strategies not only in India but also across the South Asian diaspora. The evidence supports the adoption of these therapies for better BP control with minimal risk, ultimately reducing the burden of cardiovascular diseases.

Reference:

1. Guerrero-García, C., & Rubio-Guerra, A. F. (2018). Combination therapy in the treatment of hypertension. Drugs in context, 7, 212531. https://doi.org/10.7573/dic.212531

(Input from various sources)

(Rehash/Ankur Deka/MSM)