GeriQBank · Paper III · Q18
Causes, treatment and prevention of deep vein thrombosis
- Chapter
- Cardiovascular System & Thromboembolism
- Years asked
- Not recorded in the source
- Frequency
- Set 2× in Paper III (2009–2025)
As set in the university paper
Causes, treatment and prevention of deep vein thrombosis.
Paper III · Cardiovascular Medicine · asked ×2 · 7-mark note · see in paper list
Answer framework
- Definition and significance — proximal DVT and its risks; a disease of old age
- Causes — Virchow's triad; acquired factors; ageing contributors; inherited and acquired thrombophilia; when to suspect thrombophilia
- Clinical features and diagnosis — symptoms and differentials; Wells score with ultrasound or D-dimer; age-adjusted D-dimer; occult malignancy
- Treatment — DOACs first; LMWH and warfarin; duration; antiphospholipid syndrome; adjuncts (mobilisation, stockings, thrombolysis, IVC filters)
- Prevention — admission risk assessment; mechanical and pharmacological methods; duration after surgery; thrombophilia without prior thrombosis
- Recent updates — DOACs and outpatient care, reduced-dose extended therapy, stockings, IVC filters, aspirin after arthroplasty, Indian practice
An exam answer plan drawn from the detailed answer below. Use it to attempt the question first.
Detailed answer
Pro · free in betaAttempt it firstOutline your answer as a 7-mark note before revealing it — definition, causes, evaluation, management and the geriatric angle.Reveal answer
Short revision answer
- DVT is thrombus in the deep veins, usually of the leg; proximal (popliteal and above) DVT carries the highest risk of PE and post-thrombotic syndrome. Venous thrombosis is primarily a disease of old age, and asymptomatic DVT is common in older medical inpatients.
- Causes follow Virchow's triad (stasis, endothelial injury, hypercoagulability): immobility, surgery (hip, knee, pelvis), fracture, cancer, heart failure, stroke, sepsis, dehydration, long travel, venous catheters and oestrogens. Ageing adds a weaker muscle pump, higher fibrinogen and frailty.
- Inherited thrombophilia becomes manifest in up to 50% of cases under these circumstances: factor V Leiden (the commonest; a substitution at position 1691 causing APC resistance), prothrombin 20210A, and antithrombin, protein C and protein S deficiency. Acquired causes: antiphospholipid syndrome, myeloproliferative disease and PNH.
- Presentation: unilateral pain, swelling, warmth and calf tenderness; differentials include cellulitis, ruptured Baker's cyst and haematoma. Confirm objectively before treating: Wells "likely" → ultrasound; "unlikely" → D-dimer (age-adjusted: age × 10 µg/L above 50).
- In unprovoked DVT, look for occult cancer with a focused history, examination, basic bloods and age-appropriate screening, not blanket imaging.
- Treat with a DOAC first-line (apixaban and rivaroxaban need no lead-in; dabigatran and edoxaban need at least 5 days of LMWH first), or LMWH overlapping with warfarin (INR 2.0–3.0). Treat for three to six months; consider lifelong treatment after recurrence. Triple-positive antiphospholipid syndrome needs warfarin, not a DOAC.
- Compression stockings relieve symptoms but do not prevent post-thrombotic syndrome. Reserve thrombolysis for limb-threatening iliofemoral DVT, and an IVC filter for when anticoagulation is absolutely contraindicated, removing it promptly.
- Prevention: risk-assess every admission (Padua or Caprini). Use mechanical methods (mobilisation, hydration, stockings, intermittent pneumatic compression) when bleeding risk is high; otherwise LMWH, fondaparinux or a DOAC — for up to 35 days after hip surgery and 14 days after knee replacement.
- Updates: DOACs are preferred, and low-risk DVT can be managed as an outpatient. Reduced-dose extended therapy (apixaban 2.5 mg twice daily, rivaroxaban 10 mg daily) reduces recurrence with little extra bleeding. Aspirin is acceptable extended prophylaxis after arthroplasty. In India, VTE after surgery is as common as in the West, and mandatory admission risk assessment is the key fix.
Condensed by GeriClinics from the detailed answer below, with no new facts added.
15-MARK ANSWER | 18 POINTS
Definition and Significance
Deep vein thrombosis (DVT) is thrombus formation within the deep venous system, most often of the lower limb; proximal (popliteal and above) DVT carries the greatest risk of pulmonary embolism and of post-thrombotic syndrome.
Venous thrombosis is primarily a disease of old age. Asymptomatic DVT is common on admission among older medical inpatients, so a high index of suspicion is required.
Causes
Virchow's triad: venous stasis, endothelial injury, and hypercoagulability.
Circumstantial/acquired factors: immobilisation and hospitalisation, surgery — particularly to the hip, knee and pelvis — fracture, malignancy, obesity, heart failure, stroke with limb paresis, sepsis, dehydration, long-distance travel, central venous catheters, nephrotic syndrome and oestrogen therapy.
Ageing-specific contributors: reduced mobility and muscle pump action, higher fibrinogen levels, altered platelet function, increased prevalence of malignancy and heart failure, and frailty (an independent predictor of VTE).
Inherited thrombophilia is manifest in up to 50% of cases under the above circumstances: factor V Leiden (commonest; base substitution at position 1691 producing activated protein C resistance), prothrombin 20210A allele, and deficiencies of antithrombin, protein C and protein S (autosomal dominant, heterozygous only — the homozygous state is incompatible with life).
Acquired thrombophilia: antiphospholipid syndrome (lupus anticoagulant, anti-β2-glycoprotein-1 and anticardiolipin antibodies), myeloproliferative disease and paroxysmal nocturnal haemoglobinuria.
Suspect thrombophilia when thrombosis is unusually extensive, occurs at an unusual site, is spontaneous or recurrent, or there is a positive family history — though patients may present for the first time in old age.
Clinical Features and Diagnosis
Unilateral limb pain, swelling, warmth, erythema, dilated superficial veins and calf tenderness; phlegmasia in massive iliofemoral thrombosis. Differential diagnosis includes cellulitis, ruptured Baker's cyst, lymphoedema, chronic venous insufficiency and haematoma.
Objective validation of the diagnosis must always precede treatment. Use the two-level modified Wells score: "DVT likely" → complete venous ultrasonography; "DVT unlikely" → D-dimer, and if negative no further action.
Use the age-adjusted D-dimer (age × 10 µg/L above 50 years); D-dimer specificity is poor in the elderly because of comorbidity, infection and malignancy.
Consider occult malignancy in unprovoked DVT — a focused history, examination, basic bloods, and age-appropriate cancer screening rather than indiscriminate whole-body imaging.
Treatment
First choice: a DOAC in the absence of cancer or severe renal impairment. Apixaban and rivaroxaban need no parenteral lead-in; dabigatran and edoxaban require at least 5 days of LMWH first. Doses as in Q17.
Alternative: initial LMWH (or unfractionated heparin if renal failure or a need for rapid reversibility) overlapping with warfarin to a target INR 2.0–3.0. LMWH is the anticoagulant of choice in malignancy-associated thrombosis, where it confers a survival advantage.
Duration: three to six months in older patients. Consider lifelong anticoagulation after recurrent thrombosis, starting with a target INR of 2–3 and increasing to 3–4 if further thrombosis occurs while anticoagulated. Triple-positive antiphospholipid syndrome must be treated with warfarin at the higher target range, not a DOAC.
Adjuncts: early mobilisation and graduated compression stockings for symptom relief (they do not reliably prevent post-thrombotic syndrome); catheter-directed thrombolysis only for limb-threatening iliofemoral thrombosis; inferior vena cava filter only when anticoagulation is absolutely contraindicated, with removal as soon as anticoagulation can start.
Prevention
Risk assessment for every hospital admission (Padua or Caprini score) with reassessment when the clinical state changes. Pathy's emphasises that thromboprophylaxis of both surgical and medical patients at medium and high risk is increasingly recognised and practised.
Methods. Mechanical — early mobilisation, adequate hydration, graduated compression stockings and intermittent pneumatic compression (the options of choice when bleeding risk is high, and contraindicated in severe peripheral arterial disease). Pharmacological — LMWH once daily (dose-reduced in renal impairment), unfractionated heparin if creatinine clearance is very low, fondaparinux, or reduced-dose DOACs for extended out-of-hospital prophylaxis after high-risk orthopaedic surgery such as hip and knee replacement. Duration: for the admission in medical patients; up to 35 days after hip replacement or hip fracture and 14 days after knee replacement. Also address modifiable factors — avoid dehydration, treat heart failure and infection, minimise immobility, and review oestrogens and other precipitants. In thrombophilia without prior thrombosis, management consists of adequate prophylaxis at times of increased risk such as surgery and immobilisation, rather than continuous anticoagulation.
Latest Updates (2023–Present)
ASH and ACCP guidance now favour DOACs over LMWH-warfarin for most acute DVT, including in the elderly, and support outpatient management of low-risk DVT with defined follow-up.
Extended low-dose secondary prevention is the major change: apixaban 2.5 mg twice daily or rivaroxaban 10 mg once daily after the initial treatment phase reduces recurrence with little excess bleeding (AMPLIFY-EXT, EINSTEIN-CHOICE), and API-CAT (NEJM 2025) confirmed non-inferiority with less bleeding for reduced-dose apixaban in cancer-associated VTE.
Compression stockings: the SOX and IDEAL-DVT trials showed that routine two-year elastic compression does not prevent post-thrombotic syndrome; current practice is symptom-guided, individualised compression rather than universal prescription.
IVC filters: the evidence (PREPIC-2 and subsequent registries) shows no mortality benefit and significant filter-related complications; retrievable filters should be removed promptly, and a formal retrieval pathway is now expected. Aspirin is an acceptable extended-prophylaxis option after elective hip and knee arthroplasty (CRISTAL and related trials), which matters in resource-limited Indian practice.
India: VTE was historically considered rare in Indians, but hospital-based studies show rates comparable to Western populations after major surgery; under-use of prophylaxis in medical wards remains a documented gap, and mandatory admission risk assessment is the single most effective corrective step.
Current Practice Update
Textbook position Current evidence (2023–2026)
Treatment "initially with heparin, DOAC monotherapy (apixaban, rivaroxaban) is first-line, with no parenteral lead-in. subsequently with oral warfarin".
Extended treatment not indicated in the Reduced-dose extended therapy is evidence-based and bleeds less than full dose. elderly.
Compression stockings recommended after Not effective for preventing post-thrombotic syndrome; use for symptom relief only.
DVT.
LMWH for malignancy-associated thrombosis. DOACs are now first-line for most cancer-associated VTE, except luminal GI and GU tumours where LMWH is preferred.
Examiner's Tip
Open with Virchow's triad, then write: "Objective validation of the diagnosis of venous thromboembolic disease should always precede the initiation of treatment." · "In up to half of cases of venous thrombosis an underlying genetic predisposition becomes manifest under circumstantial risk." · "Factor V Leiden is the commonest inherited prothrombotic disorder, caused by a single base substitution at position 1691 producing resistance to activated protein C." · "Extended thromboprophylaxis is given for up to 35 days after hip replacement and 14 days after knee replacement."
Appendix — Rapid Revision Grid
NIGHT-BEFORE RECALL
Numbers you must be able to quote
Item Value
BNP / NT-proBNP threshold for further >35 pg/mL / >125 pg/mL investigation (non-acute)
BNP favouring cardiac cause of acute dyspnoea >300 pg/mL Ejection fraction categories HFrEF ≤40%, HFmrEF 41–49%, HFpEF ≥50% Digoxin dose and level in patients >70 0.125 mg/day; target 0.5–0.9 ng/mL ARNI washout after ACE inhibitor 36 hours HF prevalence >80 years; 2-yr and 5-yr mortality 13–14%; 60% and 75% AF prevalence at 80; annual stroke risk at 80–89 5–15%; 23.5% Warfarin vs aspirin in AF (relative risk reduction 64% vs 22% of stroke)
CHA₂DS₂-VASc maximum / CHA₂DS₂-VA 9 / 8 (sex removed, ESC 2024)
maximum INR ranges 2.0–3.0 (VTE, AF); 3.0–4.5 (recurrent VTE, mechanical valves)
Heparin monitoring UFH: APTT ratio 1.5–2; LMWH: anti-Xa assay Age-adjusted D-dimer cut-off Age × 10 µg/L in patients >50 (ADJUST-PE)
VTE: proportion in >65s; incidence >80 years ≈60%; 8 per 1000 person-years VTE anticoagulation duration in the elderly 3–6 months (Pathy's)
30-day mortality after VTE (≥65 vs <65) 11% vs 4% DOAC major bleeding in ≥75s vs VKA Relative risk ≈0.49 Extended orthopaedic thromboprophylaxis Up to 35 days (hip); 14 days (knee)
Statin time-to-benefit in primary prevention ≥2 years Statin myopathy CK thresholds Myositis <10× ULN; rhabdomyolysis >10× ULN; act on ALT/AST >3× ULN IE in the elderly: incidence and mortality vs 4× incidence; 2× mortality; ≈50% of all cases younger 2025 ACC/AHA BP target <130/80 mmHg, with encouragement toward SBP <120 2024 ESC BP target Systolic 120–129 mmHg (relaxed if ≥85, frail, or orthostatic hypotension)
Trial names by topic
Topic Trials
Hypertension in the elderly SHEP, Syst-Eur, HYVET, SPRINT-Senior, STEP, ESPRIT, BPROAD, PARTAGE, CAFE HFrEF CONSENSUS, SENIORS, SHIFT (ivabradine), PARADIGM-HF (ARNI), DAPA-HF, EMPEROR-Reduced, STRONG-HF, VICTORIA HFpEF CHARM-Preserved, I-PRESERVE, PEP-CHF, TOPCAT, PARAGON-HF (all neutral) → EMPEROR-Preserved, DELIVER, FINEARTS-HF, STEP-HFpEF, SUMMIT Cardiomyopathy ATTR-ACT (tafamidis), ATTRibute-CM (acoramidis), HELIOS-B (vutrisiran), EXPLORER-HCM/VALOR-HCM (mavacamten), SEQUOIA-HCM (aficamten), TRED-HF Atrial fibrillation AFFIRM, RACE/RACE II, BAFTA, EAST-AFNET 4, NOAH-AFNET 6, ARTESIA, LAAOS III, OPTION, OCEANIC-AF Pacing CTOPP, MOST, UKPACE, BLOCK HF; 2023 HRS/APHRS/LAHRS physiologic pacing guideline Statins PROSPER, HPS, LIPS, ALLHAT-LLT, EWTOPIA 75, CLEAR Outcomes, STAREE (awaited) Anticoagulation / VTE ADJUST-PE, AMPLIFY-EXT, EINSTEIN-CHOICE, API-CAT, PAUSE / PAUSE-2, BRIDGE, BRUISE CONTROL-2, PREPIC-2, SOX, ANNEXA-I Endocarditis POET (partial oral therapy); 2023 Duke-ISCVID criteria; 2023 ESC IE guideline Eight lines that earn marks in any cardiovascular geriatrics answer
"Older patients are systematically under-represented in cardiovascular trials, so guideline recommendations are largely extrapolated."
"Presentation is frequently atypical — delirium, falls, anorexia and functional decline rather than classical symptoms."
"Treatment intensity should be proportionate to functional status, comorbidity and life expectancy, not to chronological age."
"Start low, go slow, and review renal function and electrolytes after every dose change."
"Time-to-benefit must be shorter than remaining life expectancy before a preventive drug is started."
"Neither falls risk nor dementia is by itself a contraindication to anticoagulation."
"Deprescribing is an active clinical decision, not a failure of care."
"Involve the multidisciplinary team, and discuss goals of care and advance planning before the terminal admission."
Indian Practice — Points to Weave In
Hypertension: LASI Wave 1 — prevalence ≈46% in adults ≥45 years, control only ≈32%. IHCI (ICMR/MoHFW/WHO-India) raised control in enrolled cohorts from ≈26% to ≈60% using standardised protocols, single-pill combinations and free drugs through Ayushman Arogya Mandirs; NPHCE provides the geriatric service framework. Heart failure: less ischaemic and more rheumatic, hypertensive and idiopathic dilated cardiomyopathy; patients present younger and later in the disease course.
Atrial fibrillation: rheumatic (valvular) AF remains common — these patients require warfarin, not a DOAC. Cost and INR access are the practical constraints.
Endocarditis: rheumatic valve disease with viridans streptococci is still a major pattern alongside the degenerative pattern of high-income countries.
VTE: once thought rare in Indians, but post-surgical rates are comparable to Western data; under-use of prophylaxis in medical wards is the documented gap. Aspirin is an acceptable extended prophylaxis option after arthroplasty in resource-limited settings.
Restrictive cardiomyopathy: remember endomyocardial fibrosis in the Indian differential diagnosis. End of document. Textbook content is drawn from Pathy's Principles and Practice of Geriatric Medicine (6th edition) and Essentials of Clinical Geriatrics (7th edition). Material dated 2023 onward is drawn from current peer-reviewed literature and professional society guidance and is presented separately under "Latest Updates" and "Current Practice Update" in each answer. Where the uploaded textbooks do not cover a topic, this has been stated explicitly.
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References
- PAPERS-2-3-4_COMBINED.pdf — page 729
- GeriQBank source PDF — p. 729
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