What is the impact of PRIME on real-life diabetic nephropathy?

Preserving cardiac function in the hypertensive patient: why renal parameters hold the key

The relationship between cardiovascular and renal pathologies is well recognized in advanced nephropathy and heart failure, but in early disease it has received less attention. Consequently, microalbuminuria screening and interventions that treat early nephropathy remain under-utilized cardioprotective strategies in the hypertensive patient. Agents that delay the progression of renal disease are likely to be cardioprotective by lessening the systemic consequences of renal dysfunction and may have additional cardioprotective effects by exerting beneficial effects on endothelia elsewhere in the body and within the heart. A critical driving factor within both renal and wider cardiovascular pathologies is overactivation of the renin-angiotensin-aldosterone system (RAAS). Accordingly, RAAS-directed antihypertensive agents including both angiotensin converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) have been demonstrated to have renoprotective effects. In major prospective trials, two ARBs, losartan and irbesartan, have been demonstrated to be renoprotective in patients with frank proteinuria, and one ARB, irbesartan, has been shown to have renoprotective properties in patients with microalbuminuria. For patients with incipient or frank renal dysfunction, an aggressive RAAS-based approach to hypertension management, combining potent blood pressure control with proven renoprotection, may therefore constitute a key component of therapy targeted towards long-term cardioprotection.

Lowering blood pressure for cardiovascular risk reduction

The association between blood pressure and cardiovascular risk is continuous, with no known lower threshold; epidemiologically, the lower the blood pressure, the better. In reality, the relationship must be J- or U-shaped, as a blood pressure of zero is associated with 100% mortality. However, the level of blood pressure control below which risk increases is well below that achieved in clinical practice, and reducing blood pressure is a cornerstone of strategies to reduce cardiovascular risk. Even relatively small reductions in blood pressure (systolic blood pressure 10-12 mmHg, diastolic blood pressure 5-6 mmHg) substantially reduce cardiovascular risk. Optimal cardiovascular protection is achievable through early and aggressive blood pressure control, but precisely which agents confer the greatest benefits for cardiovascular protection remains widely debated. Angiotensin II receptor blockers (ARBs) appear to be unique in providing additional protection beyond blood pressure control, whereas similar claims for other agents do not withstand close scrutiny. Nearly all patients with hypertension require several antihypertensive treatments to reach their target blood pressure, and it is important to choose treatments that are well tolerated and have complementary modes of action. For this reason, ARBs such as telmisartan emerge as logical choices for combination therapy, particularly when combined with a diuretic, as they fulfil all the essential requirements for combination therapy and are effective in a wide range of different types of patient. Regrettably, a rigorous approach to blood pressure control using multiple agents is still rare in general practice, partly because of a lack of understanding and partly because of 'professional non-compliance'. Prescribing habits must change, and soon, if we are to avoid an upsurge in cardiovascular complications.