Coronary atherosclerosis is a silent killer, but we have tools to stop it
Coronary artery disease, driven primarily by atherosclerosis, remains the leading cause of death in the United States, claiming tens of thousands of lives annually. Despite its prominence, heart disease is one of the most preventable conditions, with numerous therapies, including statins and PCSK9 inhibitors, capable of halting its progression. Yet, heart disease continues to be the top killer, a tragic paradox that deserves closer examination. A recent study sheds light on this phenomenon, highlighting the importance of LDL cholesterol (LDL-C) reduction in preventing cardiovascular disease.
The Study: Unveiling Hidden Atherosclerosis
The study conducted by Faridi et al. analyzed data from the Miami Heart Study, focusing on participants aged 40-65 who showed no clinical signs of cardiovascular disease (CVD) at the time of enrollment. With a cohort of 1,033 relatively healthy participants, the study aimed to assess the prevalence of coronary atherosclerosis, specifically coronary plaque and calcification, using advanced imaging techniques such as coronary artery calcium (CAC) scans and coronary computed tomography angiography (CCTA).
Despite being classified as low risk based on their exclusion of high-risk factors like hypertension, diabetes, smoking, and lipid-lowering medication, a surprising percentage of participants showed evidence of early atherosclerosis. Around 36% of participants had coronary plaque, and over 25% had CAC scores greater than zero, indicating early calcification. These findings challenge the common belief that only those with apparent risk factors suffer from coronary artery disease. They suggest that even individuals who appear healthy may have silent, asymptomatic atherosclerosis that could progress unnoticed until a serious cardiovascular event occurs.
The Role of LDL and ApoB in Atherosclerosis
The study’s primary focus was the association between lipoprotein levels, particularly LDL-C, non-HDL-C, and apolipoprotein B (apoB), and the prevalence of coronary plaque. The findings revealed a strong linear relationship between the levels of these lipoproteins and the risk of coronary atherosclerosis. Each 10 mg/dL increase in LDL-C, non-HDL-C, and apoB corresponded to a significant increase in the risk of plaque formation. Of particular note was the association with apoB, a protein found on atherogenic lipoproteins like LDL. As expected, apoB levels showed a stronger association with coronary plaque than LDL-C or non-HDL-C, underscoring the importance of apoB-containing lipoproteins in the development of atherosclerosis.
The results further indicated that this relationship was consistent even at lower levels of LDL-C, challenging the current understanding of “optimal” LDL-C levels. Current guidelines recommend an LDL-C level of less than 100 mg/dL as optimal, but the study found that the risk for plaque formation continued to rise even at levels well below this threshold. This suggests that, contrary to popular belief, lower LDL-C levels may be even more beneficial for reducing the risk of coronary artery disease, particularly in individuals who may be genetically predisposed to high apoB levels.
A Silent Disease with Alarming Prevalence
Faridi et al.’s findings underscore the silent nature of atherosclerosis, particularly among individuals who are classified as low risk. Despite the absence of symptoms, these individuals often carry hidden plaque in their coronary arteries. In fact, even among those considered to have “optimal” risk factors, nearly 21% had coronary plaque, and 14.7% had signs of early-stage calcification. These statistics are alarming, as they suggest that coronary artery disease can develop silently over time, long before symptoms like chest pain or shortness of breath manifest.
The data from this study also suggest that a significant portion of the population may be unaware of their elevated risk for heart disease, as they don’t experience noticeable symptoms. Without routine screenings or proactive testing, many individuals may unknowingly carry the disease until it reaches a more advanced stage, potentially resulting in fatal heart attacks or strokes. This highlights the critical need for early detection, particularly among those with elevated lipid levels, even in the absence of other obvious risk factors.
The Importance of Early Detection and Treatment
The study by Faridi et al. serves as a reminder that cardiovascular disease can affect anyone, regardless of apparent risk. Many individuals may be unaware of the buildup of plaque in their arteries, which can be identified through tests such as CAC scans and CCTA. Importantly, these screenings can reveal atherosclerosis long before it leads to symptomatic events. Early detection allows for timely interventions, such as lipid-lowering treatments, which can slow or halt the progression of the disease.
This study also reinforces the importance of reducing LDL and apoB-containing lipoproteins as a means of preventing atherosclerosis and associated mortality. Statins, PCSK9 inhibitors, and lifestyle changes aimed at lowering these lipoproteins have proven to be effective in reducing the risk of heart disease and improving long-term outcomes. While these treatments are widely available, Faridi et al.'s findings suggest that they are underutilized, especially among those who do not yet show symptoms of CVD.
The Ongoing Challenge of Heart Disease
Despite the effectiveness of available treatments, coronary artery disease continues to be a leading cause of death worldwide. One of the primary reasons for this is the widespread lack of awareness about the early stages of the disease. Many individuals are not tested for atherosclerosis until it is too late, and by the time symptoms appear, the damage to the heart may already be done. Faridi et al.'s data suggest that millions of people may unknowingly carry early-stage coronary atherosclerosis, which increases their risk of heart attacks and strokes.
In order to combat this silent killer, greater emphasis must be placed on proactive screenings and the early detection of atherosclerosis, particularly in individuals with elevated lipoprotein levels. By identifying at-risk individuals before they develop symptomatic heart disease, we can reduce the burden of cardiovascular mortality and improve overall public health. As the study shows, coronary artery disease is not limited to those with overt risk factors – it can affect anyone, making early detection and treatment more crucial than ever.
Conclusion
The study by Faridi et al. highlights the prevalence of coronary atherosclerosis in asymptomatic, low-risk individuals and underscores the importance of proactive testing and early intervention. Elevated levels of apoB-containing lipoproteins, even at levels below the current “optimal” thresholds, are strongly associated with coronary plaque and atherosclerosis. These findings reinforce the need for early detection through imaging tests like CAC scans and CCTA, which can reveal hidden disease long before it leads to major cardiovascular events. While effective treatments are available to slow or stop atherosclerosis, they are often underutilized, particularly among those without obvious symptoms. Addressing this gap in care could save thousands of lives and reduce mortality from heart disease, ultimately helping to mitigate one of the world’s leading causes of death.
Update from Peter Attia, on 2024-08-17Source