How do you calculate Atherosclerotic Cardiovascular Disease (ASCVD) risk for a former smoker who quit a decade ago but vapes daily, with potential Type 2 diabetes remission or a Hemoglobin A1c (HbA1c) under 5.7%?

ASCVD Risk Calculation in Former Smokers Who Vape and Patients with Diabetes Remission

Smoking Status Classification for ASCVD Risk Calculation

For a former smoker who quit a decade ago but vapes daily, classify them as a current smoker when calculating ASCVD risk using the Pooled Cohort Equations. The ACC/AHA Pooled Cohort Equations use a binary smoking variable (current smoker: yes/no) and do not account for time since cessation or alternative nicotine delivery systems 1. Electronic nicotine delivery systems (ENDS) are not FDA-approved smoking cessation tools, and evidence shows they do not increase smoking cessation rates—in fact, daily vaping is associated with reduced tobacco abstinence compared to matched controls (14.7 percentage point lower abstinence, 95% CI -20.2 to -9.2, P<0.001) 2.

Key Considerations for Vaping Status

• Daily vaping maintains nicotine addiction and cardiovascular risk. The 2019 ACC/AHA Primary Prevention Guidelines explicitly state that ENDS are not recommended as a tobacco treatment method, as evidence on their effectiveness for cessation is insufficient and they may be potentially harmful 1.

• The cardiovascular risk reduction timeline from smoking cessation is disrupted by continued nicotine exposure. Former smokers who quit for 10-14 years show cardiovascular disease mortality risk that remains 20% elevated compared to never smokers (HR 1.20,95% CI 1.02-1.41), but this assumes complete tobacco/nicotine abstinence 1.

• Nicotine exposure through vaping likely prevents the vascular healing that occurs with complete cessation. Tobacco smoking causes multiple deleterious effects including increased free radical generation, reduced nitric oxide bioavailability, enhanced leukocyte and platelet activation, and prothrombotic alterations—many of which are mediated by nicotine itself 1.

Practical Algorithm for Smoking Status Entry

1. If the patient uses any ENDS product daily → Enter "Yes" for current smoker 1
2. If the patient quit all tobacco/nicotine products ≥1 year ago → Enter "No" for current smoker 1
3. If uncertain about frequency or recent quit attempt → Classify as current smoker to avoid underestimating risk 1

Diabetes Status Classification for ASCVD Risk Calculation

For patients with Type 2 diabetes "remission" or HbA1c <5.7%, you must still classify them as having diabetes if they have a documented history of diabetes, regardless of current glycemic control. The Pooled Cohort Equations use diabetes as a binary variable (yes/no) based on history, not current metabolic status 1.

Rationale for Maintaining Diabetes Classification

• Diabetes remission does not eliminate the accumulated cardiovascular damage from prior hyperglycemia. The metabolic memory phenomenon means that prior periods of hyperglycemia continue to influence cardiovascular risk even after glycemic normalization 1.

• The Pooled Cohort Equations were derived from cohorts where diabetes was defined by history or treatment, not by current HbA1c alone. Changing this definition would invalidate the risk prediction model 1.

• Patients who achieve HbA1c <5.7% through intensive lifestyle modification or medication still carry the diagnosis. The cardiovascular risk associated with diabetes history persists independent of current glycemic control 1.

Special Scenarios Requiring Clinical Judgment

• If HbA1c <5.7% was achieved through bariatric surgery with sustained remission >5 years: Consider the patient may have lower risk than the calculator suggests, but still enter "Yes" for diabetes and discuss risk-enhancing factors 1.

• If the patient was misdiagnosed (e.g., had stress hyperglycemia, not true diabetes): Enter "No" for diabetes only if you have clear documentation that the original diagnosis was incorrect 1.

• If prediabetes (HbA1c 5.7-6.4%) without prior diabetes diagnosis: Enter "No" for diabetes, but recognize this as a risk-enhancing factor that may favor statin therapy in intermediate-risk patients 1.

Critical Pitfall to Avoid

Never enter "No" for diabetes based solely on current HbA1c <5.7% if there is any documented history of diabetes diagnosis or treatment. This would significantly underestimate cardiovascular risk and could lead to undertreatment with statins and other preventive therapies 1. The risk calculator's diabetes variable captures lifetime exposure to hyperglycemia and its vascular consequences, not just current metabolic status 1.

Additional Risk-Enhancing Factors to Document

Beyond the calculator inputs, document these factors that may influence treatment decisions in borderline cases 1:

• For the vaping patient: Total pack-years from prior cigarette smoking, duration of vaping, presence of vaping-related symptoms
• For the diabetes remission patient: Duration of prior diabetes, peak HbA1c levels, presence of microvascular complications (retinopathy, nephropathy, neuropathy), method of achieving remission
• Both patients: Family history of premature ASCVD, chronic kidney disease (eGFR <60), metabolic syndrome components, chronic inflammatory conditions, lipoprotein(a) if measured 1