Heart Disease: The World's Leading Killer

What is Cardiovascular Disease?

Cardiovascular disease (CVD) is a group of disorders affecting the heart and blood vessels. It includes coronary artery disease, stroke, heart failure, arrhythmias, and peripheral arterial disease. While often discussed as a single entity, CVD encompasses a range of conditions that share common risk factors and underlying mechanisms.

The underlying process in most CVD is atherosclerosis, the gradual buildup of fatty plaques in artery walls. Over decades, these plaques narrow arteries and can rupture, triggering blood clots that cause heart attacks and strokes.

The Global Burden

CVD kills more people than any other cause: 17.9 million deaths annually, representing 32% of all global deaths.[1] About 85% of these deaths are due to heart attacks and strokes.

The burden falls disproportionately on low- and middle-income countries, where more than three-quarters of CVD deaths occur. In these regions, people often lack access to early detection and treatment, and preventive public health measures are underfunded.

In the United States alone:

• Someone has a heart attack every 40 seconds
• Someone has a stroke every 40 seconds
• Heart disease costs the US $219 billion annually[2]
• About 1 in 5 deaths is from heart disease

Understanding Atherosclerosis

Atherosclerosis begins in childhood with fatty streaks in arteries. Over decades, these evolve into plaques containing cholesterol, inflammatory cells, and calcium. The process is driven by:

1. LDL cholesterol: "Bad" cholesterol penetrates artery walls and becomes oxidized
2. Inflammation: Immune cells try to clean up the cholesterol, forming foam cells
3. Plaque formation: Dead cells and cholesterol accumulate under a fibrous cap
4. Plaque rupture: Unstable plaques can rupture, triggering clot formation

The revolutionary insight came from the Framingham Heart Study, launched in 1948, which identified key risk factors: high blood pressure, high cholesterol, smoking, diabetes, and obesity.[5] These remain the targets of prevention today.

Risk Factors

Non-modifiable risk factors include age (risk increases with age), sex (men develop CVD earlier), and family history of premature heart disease.

Prevention

The extraordinary news is that 80% of premature heart disease and stroke is preventable.[1] Prevention strategies include:

Lifestyle Modifications

• Diet: Mediterranean or DASH diet; limit sodium, saturated fat, added sugars
• Exercise: At least 150 minutes moderate aerobic activity weekly
• Smoking cessation: Risk drops significantly within years of quitting
• Weight management: Even modest weight loss improves risk factors
• Limit alcohol: Excessive drinking raises blood pressure

Medications

• Statins: Lower LDL cholesterol; reduce heart attack risk by 25-35%[4]
• Blood pressure medications: ACE inhibitors, ARBs, calcium channel blockers
• Aspirin: For secondary prevention (those who've had events)
• PCSK9 inhibitors: Powerful cholesterol-lowering for high-risk patients

Treatment Advances

Treatment of CVD has been transformed over the past 50 years:

• Cardiac catheterization: Angioplasty and stenting to open blocked arteries
• Coronary bypass surgery: Rerouting blood around blockages
• Thrombolytics: Clot-busting drugs for acute heart attacks and strokes
• Implantable devices: Pacemakers, defibrillators, mechanical heart pumps
• Heart transplantation: For end-stage heart failure

Perhaps most impactful has been the shift to rapid reperfusion, opening blocked arteries within 90 minutes of a heart attack using angioplasty or thrombolytics. "Time is muscle" has become a medical mantra.

The Cholesterol Story

The discovery that lowering cholesterol prevents heart disease is one of medicine's greatest achievements. The statin drugs, introduced in the 1980s, have prevented millions of heart attacks and strokes.

Recent advances have pushed the boundaries further. PCSK9 inhibitors can lower LDL to unprecedented levels, and trials show that "lower is better," as there appears to be no LDL level below which risk stops declining.

"Heart disease is largely a disease of lifestyle. The vast majority of cases are preventable through changes in diet, exercise, and risk factor management."

The Future

Emerging approaches include:

• Gene therapy: One-time treatments to permanently lower cholesterol
• RNA therapies: Inclisiran, a twice-yearly injection for cholesterol control
• Inflammation targeting: Drugs targeting residual inflammatory risk
• AI prediction: Machine learning to identify high-risk individuals
• Regenerative medicine: Growing new heart tissue

Despite advances in treatment, prevention remains paramount. As the global epidemic of obesity and diabetes continues, so does the burden of cardiovascular disease. The tools exist to prevent most cases; the challenge is implementation.