cardio/respiratory: CV clinical basics + risk assessment

atherosclerosis

• a condition in which plaque builds up inside the arteries

  • the plaque consists of fatty deposits, cholesterol, calcium, and other substances found in the blood

• as the plaque grows, it can harden and calcify, further narrowing the arteries and stiffening them

  • this reduces their flexibility and ability to respond to changes in blood pressure

• over time, this plaque hardens and narrows the arteries, leading to reduced blood flow to vital organs and tissues

• the plaque may rupture, triggering the formation of a blood clot at the site

  • this can partially or completely block blood flow, leading to serious conditions like heart attack or stroke

• the reduced blood flow can also cause conditions such as angina (chest pain), peripheral artery disease (PAD), or chronic kidney disease, depending on which arteries are affected

types of cardiovascular disease (CVD)

• atherosclerotic CVD (ASCVD)

• non-atherosclerotic CVD

atherosclerotic CVD (ASCVD)

• atherosclerosis that causes ASCVD medical conditions in the coronary arteries

  • eg. heart attack (MI)

• or, atherosclerosis that causes ASCVD medical conditions in the brain, kidney, aorta, mesentary, or peripheral arteries

  • eg. ischemic stroke or CVA

non-atherosclerotic CVD (non-ASCVD)

• non-athersclerotic factors cause non-ASCVD medical conditions in the heart or vasculature, such as

  • hemorrhagic stroke

  • heart failure

  • arrhythmias (eg. Afib)

  • venous thromboembolism (VTE)

    • deep vein thrombosis (DVT)

  • heart valve disorders

  • congenital heart diseases

• basically conditions that have nothing to do with plaque build-up in the arteries

coronary vessel ASCVD

• atherosclerosis that occurs in the primary blood vessels that supply oxygen and nutrients to the heart muscle (coronary arteries), including conditions such as:

  • ischemic heart disease (IHD)

    • aka coronary artery disease (CAD)

    • aka coronary heart disease (CHD)

  • chronic stable angina

  • myocardial infarction (MI)

  • acute coronary syndrome (ACS) / unstable angina

  • surgical revascularization of coronary artery

    • coronary artery bypass graft (CABG)

    • percutaneous coronary intervention (PCI)

      • coronary stent or angioplasty

non-coronary vessel ASCVD

• ischemic stroke - cerebrovascular accident (CVA)

• transient ischemic attack (TIA) - “mini stroke”

• renal artery stenosis

  • can involve single or both kidneys

• mesenteric artery disease

  • “bowel infarction”

• abdominal aortic aneurysm (AAA)

  • “triple” A

• peripheral vascular disease (PVD)

  • eg. peripheral artery disease (PAD)

    • “intermittent claudication”

• surgical revascularization of non-coronary artery (eg. AAA repair)

guidelines for CVD

• American College of Cardiology (ACC)

• American Heart Association (AHA)

primary prevention of ASCVD

• lifestyle and/or drug therapy used to reduce the risk of CVD development in adults

  • eg. clinician patient discussion on benefit vs. risk of treatment to optimize pt outcomes

  • basically, the pt has no existing clinical manifestations of ASCVD, but they may have high risk factors, so you’re aiming to reduce the risk of developing ASCVD in the first place

    • this includes interventions to reduce ASCVD risk, such as addressing risk factors

  • includes use of risk estimation tools to guide decisons on preventative care according to risk level, such as the pooled cohort equation (PCE)

pooled cohort equation (PCE)

• used in AHA/ACC guidelines on management of HTN, cholesterol, and ASCVD primary prevention

• you put in your demographics (age, race, sex, etc) and you get:

  • 10 year risk score

  • 30 year risk score

• assess risk enhancing factors and coronary artery calcium (CAC) score along with the results

limitations to the pooled cohort equation (PCE)

• validated in non-hispanic whites and african-american populations

• however, it may underestimate ASCVD risk in higher risk populations

  • eg. south asian, american-indian or puerto-rican populations

• it may also overestimate ASCVD risk in lower risk populations

  • eg. east asian or mexican populations

• it will not calculate if the LDL is ≥ 190 mg/dL

  • automatic high risk

• intended for use at base-line, to decide on lipid-lowering therapy

• lastly, it does not account for CKD or metabolic health

higher risk populations for ASCVD risk

• south asian (eg. indian or pakistani)

• american-indian

• puerto-rican

lower risk populations for ASCVD risk

• east asian (eg. korean or chinese)

• mexican

primary prevention guideline for ASCVD

• recommended interventions to lower risk of developing ASCVD

  • 20-39 yrs old: assess traditional CV risk factors every 4-6 years

  • 40-75 yrs old: routinely assess traditional CV risk factors AND routinely estimate 10-year ASCVD risk score

    • if estimated 10-year ASCVD is 5-19.9% (intermediate risk):

      • consider risk enhancing factors (REF)

      • may consider coronary artery calcium (CAC) score if risk-based decisions remain uncertain after discussing risk factors/REF

    • if 40-59 yrs old and estimated 10-year risk is < 7.5%:

      • may consider 30-year ASCVD risk score

10-year risk score (PCE)

• “short-term” risk

  • decribes the risk for a patient of developing their first ASCVD event (heart attack or stroke) within 10 years

• only applicable to patients without clinical manifestations of ASCVD (primary prevention)

• only applicable to patients who are 40-79 years old

  • in primary prevention guidelines, it’s from ages 40-75 years old)

30-year risk score (PCE)

• “long-term” or “lifetime” risk

• only applicable to patients without clinical manifestations of ASCVD (primary prevention)

• only applicable to patients who are 40-59 years old

• mostly used for clinician-patient dicussion on the importance of lifestyle and/or drug therapy

• compares risk with vs without optimal risk factor management

  • eg. 50% vs 35%

  • let’s say they get a lifetime 30% risk of developing ASCVD, but if they optimized their risk factors (like lowered their BP for example), their risk score would potentially only be 35%

10-year risk score is < 5% (PCE)

• low risk for developing ASCVD in 10 years

10-year risk score is 5-7.4% (PCE)

• borderline risk for developing ASCVD in 10 years

10-year risk score is 7.5-19.9% (PCE)

• intermediate risk for developing ASCVD in 10 years

10-year risk score is > 20% (PCE)

• high risk for developing ASCVD in 10 years

primary prevention algorithm for low risk patients

• 10-year ASCVD risk score is < 5%:

  • risk discussion: emphasize the importance of lifestyle modification to reduce risk factors

  • no drug therapy

primary prevention algorithm for borderline risk patients

• 10-year ASCVD score is 5 to <7.5%:

  • clinican-patient discussion considering risk-enhancing factors and net benefit of therapy

    • if uncertainty remains, consider CAC score and revise decision based on results

      • lifestyle modifications only or lifestyle AND drug therapy

primary prevention algorithm for intermediate risk patients

• 10-year ASCVD score is 7.5 to <20%:

  • clinican-patient discussion considering risk-enhancing factors and net benefit of therapy

    • if uncertainty remains, consider CAC score and revise decision based on results

      • lifestyle modifications only or lifestyle AND drug therapy

primary prevention algorithm for high risk patients

• 10-year ASCVD score is ≥ 20%:

  • patient should definitely start drug therapy (statins) to decrease risk AS WELL AS lifestyle modifications

  • lifestyle AND drug therapy initiation

calcium artery calcium (CAC) score

• a tool used in assessing the risk of developing ASCVD

• it quantifies the amount of calcium buildup in the coronary arteries using a CT scan, which helps to estimate the presence of atherosclerotic plaque in the arteries

  • calcium is a marker of plaque (atherosclerosis), so a higher CAC score suggests more plaque in the arteries

  • CT scan may be costly and not often covered by insurance though

• especially useful in patients with a borderline/intermediate 10-year risk score to help determine what they want to do for therapy

• for example, if someone has borderline cholesterol or hypertension, a score of 0 might suggest that aggressive treatment isn’t needed

  • on the other hand, a high CAC score would indicate a greater need for preventive therapies

• in primary prevention, the goal is to avoid the first cardiovascular event (e.g., heart attack, stroke)

  • thus, the score is a way to personalize risk assessment, helping to identify patients who may benefit from early intervention with lifestyle changes, medications like statins, or more intensive monitoring

subclinical ASCVD

• the patient falls into this classification if their CAC score is positive/high

  • don’t need to know the specifics of their CAC score, just know that these patients have a high CAC score

secondary prevention

• lifestyle and/or drug therapy used to reduce progression of existing CVD in adults

  • eg. guideline directed medical therapy (GDMT) to optimize patient outcomes

  • if the patient has any of the clinical manifestations of ASCVD, both coronary and non-coronary ASCVD, they automatically fall into this classification

  • this is because once the pt has gotten atherosclerosis in one vessel, they’re likely to get it again in other vessels, so you want to prevent this progression

  • very specific guideline-directed medical therapies

    • evidence-based medicine

  • no risk estimation needed (since they already have ASCVD, making them high risk for more ASCVD)

secondary prevention guideline for ASCVD

• recommend interventions to reduce ASCVD progression

  • routinely asses traditional CV risk factors

  • invalid to use any ASCVD risk score, CAC, or REF

  • follow guideline-directed medical therapy (GDMT) to optimize patient outcomes

traditional cardiovascular risk factors

• age

  • ≥ 55 years old for males

  • ≥ 65 years old for females

• hypercholesterolemia (dyslipidemia)

• hypertension

• diabetes mellitus

  • either type 1 or type 2

• current tobacco use (within the last 30 days)

• obesity

• physical inactivity

risk enhancing factors (REF) for primary prevention of ASCVD

1. family history of premature ASCVD

   • first-degree relative (eg. parent, child, sibling) that developed CVD before age 55 in males, or before age 65 in females

2. higher risk race/ethinicity/ancestry

   • eg. south asian, puerto-rican, american-indian

3. primary hypercholesterolemia

   • high LCL → 160-189 mg/dL

4. elevated biomarker levels

   • C reactive protein, lipoprotein a, aproprotein B, low ankle brachial index (ABI), persistently elevated hypertriglyceridemia

     • non-fasting TG ≥ 175 OR fasting TG ≥ 150 on 2-3 occasions

5. metabolic syndrome (MetS)

6. chronic kidney disease (CKD)

   • eGFR of 15-19 with or without proteinuria

   • doesn’t count if they are treated with dialysis or kidney transplantation

7. chronic inflammatory conditions

8. premature menopause or pregnancy conditions

   • menopause under age 40 or conditions such as preeclampsia, gestational diabetes/ HTN, etc

diabetes specific risk enhancers

• long- duration

  • having type 2 DM ≥ 10 years

  • type 1 DM ≥ 20 years

• nephropathy (GFR <60 and proteinuria)

• retinopathy (eye)

• neuropathy (PAD)

systolic blood pressure (SBP)

• the upper number on a blood pressure reading

diastolic blood pressure (DBP)

• the lower number on a blood pressure reading

normal blood pressure

• systolic blood pressure (upper number) is less than 120 mm Hg

• AND…

• diastolic blood pressure (lower number) is less than 80 mm Hg

  • eg. 110/74

elevated blood pressure

• systolic blood pressure is 120-129 mmHg

• AND…

• diastolic blood pressure is less than 80 mmHg

  • eg. 120/68

high blood pressure (stage 1)

• systolic blood pressure is 130-139 mmHg

• OR…

• diastolic blood pressure is 80-89 mmHg

  • eg. 135/67 or 120/87

high blood pressure (stage 2)

• systolic blood pressure is greater than 140 mmHg

• OR…

• diastolic blood pressure is greater than 90 mmHg

  • eg. 133/95 or 154/60

hypertensive crisis

• systolic blood pressure is greater than 180 mmHg

• AND/OR…

• diastolic blood pressure is greater than 120 mmHg

  • eg. 185/91 or 143/125 or 181/130

  • patient must consult with a doctor immediately

isolated systolic hypertension

• the SBP is classified as stage 1 hypertension or higher (>130 mmHg), but the DBP is classified as normal (<80 mmHg)

  • however, the higher category always applies if the systolic and diastolic BPs fall into different categories

orthostasis (aka orthostatic hypotension or postural hypotension)

• defined as a SBP that drops ≥ 20 mmHg and/or a DBP that drops ≥ 10 mmHg within 2-5 minutes of going from a sitting/laying down position to a standing position or vice/versa

• can occur with OR without symptoms

  • symptoms could include significant dizziness or syncope (passing out)

risk factors for orthostasis

• older age (>65 yrs), especially very old age (>80 yrs)

• drug therapy side effects such as hypotension, excessive sweating, or more urination

  • when it occurs, its usually due to hypovolemia, which is defined as extracellular fluid loss often with inadequate fluid intake, which causes low intravascular volume and low tissue perfusion

  • make sure they are drinking enough fluid

bradycardia

• resting HR is < 60 BPM

  • symptoms may include:

    • fatigue

    • dizziness

    • lightheadedness

    • syncope

tachycardia

• resting HR is > 100 BPM

  • symptoms may include:

    • dizziness

    • lightheadedness

    • palpitations

    • angina (chest pain)

    • SOB

basic metabolic profile (BMP)

• a common set of blood tests which evaluates certain assays such as:

  • sodium (Na+)

  • potassium (K+)

  • serum creatinine (SCr)

  • estimated glomerular filtration rate (eGFR)

  • blood urea nitrogen (BUN)

  • blood glucose (BG)

  • calcium (Ca++)

  • carbon dioxide

  • chloride (Cl-)

normal range for sodium in blood

• 135 - 145 mEq/L

hyponatremia

• less than 135 mEq/L in blood

hypernatremia

• more than 145 mEq/L in blood

normal range for potassium in blood

• 3.3 - 4.9 mEq/L

hypokalemia

• less than 3.3 mEq/L in blood

hyperkalemia

• more than 4.9 mEq/L in blood

normal range for serum creatinine (SCr)

• 0.6 - 1.1 mg/dL

  • should be interpreted with caution, and in combination with the eGFR

  • just because it may be within normal limits (WNL) doesn’t mean there is no kidney impairment

normal estimated glomerular filtration rate (eGFR)

• ≥ 60 mL/min

  • labs will use a standardized value

  • this standardizes the interpretation of kidney function without sole reliability on SCr

  • lab reports use standard calculation (MDRD equation) for estimating pt’s “renal function”

  • values may differ slightly from other estimates

    • eg. creatinine clearance (CrCl)

    • some FDA drugs that need renal dosing adjustments go based off of this value or CrCl, or sometimes even going based off of SCr

kidney function

• can determine with the help of serum creatinine (SCr) levels and estimated glomerular filtration rate (eGFR)

  • CAUTION: just because SCr is within normal limits (WNL) doesn’t necessary mean normal kidney function → you must always interpret its results in conjunction with eGFR

• pt’s age, gender, weight, and muscle mass may limit the predictability of SCr to detect “renal impairment”

chronic kidney disease (CKD)

• typically involves an eGFR < 60 mL/min with abnormal SCr

• can occur with OR without proteinuria (protein in urine)

proteinuria (aka microalbuminuria or macroalbuminuria)

• defined as an albumin-creatinine ratio (ACR) ≥ 30 mg/g

normal range for albumin-creatinine ratio (ACR)

• < 30 mg/g

  • indicates no proteinuria or insignificant proteinuria

comprehensive metabolic profile (CMP)

• includes everything in the BMP assays plus:

  • albumin

  • total protein

  • alkaline phosphatase

  • bilirubin

  • aspartate transaminase (AST or SGOT)

  • alanine transaminase (ALT or SGPT)

normal range for AST in blood

• 11 - 47 IU/L

normal range for ALT in blood

• 7 - 53 IU/L

hepatic transanimases

• AST and ALT

  • most common liver function tests (LFTs) referred to with pharmacotherapy warnings

    • some drugs, for example, need to be avoided if the ALT is greater than 3x the upper limit of normal (ULN)

  • abnormalities of these values are often based on degree of ALT or AST elevation relative to the upper limit of normal (ULN)

    • for example, “AST 2 x ULN” = AST 94 IU/L (since the AST ULN is 47 and you multiply that by 2)

    • eg. “ALT > 3 x ULN” = ALT is > 159 IU/L (since ALT ULN is 53 and you multiply that by 3)

cholesterol (lipid) profile

• includes

  • HDL-C

  • triglycerides (TG)

  • total cholesterol (total-C or TC)

  • LDL-C

    • labs report a calculated LDL-C measurement

    • this is because a direct LDL-C is a more costly and specific study

fasting lipid profile (FLP)

• the gold standard for cholesterol/lipid profile, especially when screening or managing dyslipidemia

• you want the patient to have not eaten/drank for at least 8-12 hours before

• if screening a patient for dyslipidemia, it’s reasonable to use a non-fasting profile in pts who are low risk since you wouldn’t expect high TGs anyway

  • when a pt is not fasting, the lipid profile can demonstrate higher triglycerides

formula for LDL-C on a FLP

• [TC] - [HDL-C] - [TG/5]

  • cannot calculate when TG ≥ 400 mg/dL

    • this is because triglycerides are the fatty portion of cholesterol, and too much will ruin the sample, making it an inaccurate read

    • thus, cannot accurately calculate

formula for percent LDL lowering

• [change in value (baseline value – current value) ÷ baseline value] * 100

  • baseline value = value before treatment

  • current value = value after treatment/currently

dyslipidemia

• consists of abnormally high levels of LDL-C and/or triglycerides

  • LDL-C levels are the primary focus in its management

    • the goal is to reduce the pt’s levels to target level

range for elevated LDL-C

• 70-159 mg/dL

  • may or may not treat with drug therapy comparative to the patient’s baseline risk for ASCVD

range for high LDL-C

• 160-189 mg/dL

  • targets for drug therapy in most cases

  • unless the pt has the contraindications, will almost always start with statin therapy

range for very high LDL-C

• ≥ 190 mg/dL

  • targets for drug therapy in most cases

  • unless the pt has contraindications, will almost always start with statin therapy

hyperlipidemia/hypercholesterolemia

• increases risk of ASCVD in a log-linear manner

  • basically, the higher the LDL, the higher the ASCVD risk

range for borderline high triglycerides

• 150-199 mg/dL

range for high triglycerides

• 200-499 mg/dL

range for very high (severe) triglyceridemia

• ≥ 500 mg/dL

  • increases risk for ASCVD if persistently elevated

  • also increases risk for pancreatitis

    • an acute condition leading to abdominal pain due to inflammation of the pancreas

range for moderate hypertriglyceridemia

• 150-499 mg/dL

• may increase ASCVD risk, especially if it is persistently elevated

range for persistently elevated TGs (fasting)

• TG ≥ 150 on 2-3 occasions

range for persistently elevated TGs (NON-fasting)

• TG ≥ 175 on 2-3 occasions

hypertriglyceridemia (HTG)

• often goes along with other conditions

  • for example, uncontrolled diabetes can increased TG levels

  • dietary choices can also increase TGs

non-pharmacologic approaches to CVD

• diet

  • emphasizing intake of fruits, vegetables, and whole grains

  • include low fat dairy options, poultry, fish, legumes, non-tropical vegetable oils

  • limited intake of sweets and red meats

  • reduced intake/calories from saturated fat and limit trans fat

  • 3-12g of soluble fiber per day

• exercise, primarily 150-300 minutes per week of moderate intensity or 75-150 minutes/week of vigorous intensity, especially involving all muscle groups at least twice weekly

  • limiting sedentary time

• and lifestyle changes, such as weight loss/maintenance, and smoking cessation (if applicable)

goals of treatment for dyslipidemia

• it’s NOT necessarily to get “good” LDL-C/TG numbers, but to decrease the risk of future hospitalizations due to CVD, or progression of disease

dietary supplemetation for CVD prevention/treatment

• the benefits are not fully clear, but the risks are (risk>benefit), which poses safety issues

  • eg. not FDA-regulated, which raises concerns for purity or dosage of the product

• there are also efficacy issues

  • often involves conflicting, weakly powered, small, short-term studies, and any efficacy data often focused on therapeutic target (eg. LCL-C) without any outcome data

CVA

• cerebrovascular accident

  • basically the medical term for a stroke

• 3 types of cerebrovascular accidents

  • ischemic stroke

  • hemorrhagic stroke

  • transient ischemic attack (TIA)

major ASCVD events

• myocardial infarction (MI)

• ischemic cerebrovascular accidents (CVA)