Special Issue on Hypertension from “Aamchi Mumbai”

Hypertension (HTN) is an increasing threat to global public health, a leading cause of premature death, and an important modifiable risk factor for coronary artery disease (CAD), stroke, and renal failure. The global burden of HTN is expected to increase from the current estimate of 1 billion affected individuals to 15.6 billion affected individuals by 2025.[1] Aggressive lifestyle modifications are recommended in all subjects with HTN irrespective of age, gender, race, risk factors, or associated comorbidities. Statins for primary prevention of CAD are often needed in patients with HTN. The special issue of HTN from “Aamchi Mumbai” (our Mumbai) includes contribution from diverse specialties and provides insights into specific issues which a cardiologist, internist, pulmonologist, neurologist, interventional cardiologist, or pediatrician encounter. Clinicians from across the Mumbai have put forward their views on subjects varying from BP levels to therapeutic interventions. Management of HTN in specific circumstances (e.g., pregnancy, obstructive sleep apnea (OSA), resistant and secondary HTN) have been eloquently addressed. There has been extensive debate about the most recent American College of Cardiology (ACC)/American Heart Association (AHA) and European Society of Cardiology (ESC) and European Society of Hypertension (ESH) guidelines.[2-5] Overall both guidelines agree on majority of the issues. The most important distinction is that ACC/AHA guidelines maintain that all people with blood pressure (BP) >130/80 mmHg have HTN, and BP should be lowered to <130/80 mm in all. In contrast, BP >140/90 mmHg is considered HTN by European guidelines with the goal to reduce BP <140/90 mm for all and targeting to lower levels in those with high cardiovascular (CV) risk. Newer and aggressive BP goals to control HTN have been controversial. How low systolic blood pressure (SBP) should be lowered continues to be hotly debated by various specialists. A discussion point is the balance of potential benefits versus likely harm or adverse effects. In the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial with a mean follow-up of 4.7 years, a target BP of <120 compared with 140 mmHg was not associated with a reduced risk of composite of CV events (heart attack, a stroke, or a CV death).[6] However, the incidence of stroke was significantly less. The evidence that excessive lowering with diastolic blood pressure (DBP) may compromise the cardiac outcomes (the J curve) is inconsistent.[7] Evidence with respect to BP targets in chronic kidney disease (CKD) is complex. Epidemiological studies have shown that an elevated BP is the most important determinant of the risk of stroke. The risk is almost linear and the lowering of high BP is a major factor in the impressive reduction in the stroke death rates in the recent years.[8] Meta-analyses of antihypertensive trials have demonstrated that BP lowering is more important than the particular drug class in preventing the complications such as stroke and CAD.[9] Management of HTN during hemorrhagic, ischemic, or recurrent stroke is truly challenging. During an acute phase of stroke, BP is often elevated as a protective mechanism and often declines without intervention. Secondary prevention of HTN is a key to reducing long-term morbidity and disabilities of stroke events. Similarly, strong epidemiological correlation exists between CAD and HTN. Randomized controlled trials (RCTs) have shown that BP lowering in patients with HTN produces rapid reduction in CV risk.[10] The appropriate SBP and DBP targets in patients with established CAD remain debatable. There are certain groups of drugs (angiotensin-converting enzyme inhibitor [ACEI] or angiotensin receptor blocker [ARB], and beta-blockers) which have shown particular efficacy in secondary prevention of CAD. HTN is a major risk factor in the development and progression of CKD, irrespective of cause of CKD. Reduction of albuminuria as a therapeutic target whether this parameter is a proxy for CV event reduction remains unresolved. BP lowering reduces renal perfusion pressure, it is expected and not unusual for e-GFR to be reduced by 10–20% in patients treated for HTN. This decline usually occurs in the first few weeks of treatment and then stabilizes. A cautious approach is needed to treat HTN keeping in mind age, comorbidities, end-organ damage, and individual response. The nuances of dealing with HTN in cerebrovascular disease and CAD have been addressed in this issue. HTN affects women in all phases of life and is prone to develop HTN after the third decade of life. The pathophysiology of HTN is different with unique forms of HTN associated with