What is the best course of treatment for an elderly male patient with a history of hypertension and mantle cell lymphoma in remission, presenting with symptoms of lightheadedness and shortness of breath, and taking metoprolol succinate (beta-blocker) and hydrochlorothiazide (HCTZ) (diuretic), with lab results showing hyperlipidemia and tachycardia?

Management of Elderly Male with Hypertension, Mantle Cell Lymphoma in Remission, and Cardiovascular Symptoms

Primary Recommendation

Increase metoprolol succinate to 50 mg daily as planned, discontinue or reduce hydrochlorothiazide (HCTZ) given the patient's history of dehydration-related symptoms, and continue close monitoring of blood pressure and heart rate with follow-up in 3-4 months rather than 6 months given his elevated diastolic pressures and persistent tachycardia. 1, 2

Blood Pressure Management

Current Status and Target

• The patient demonstrates consistently normotensive systolic readings but elevated diastolic pressures (high 80s to low 90s), with persistent heart rate in the 90s despite metoprolol 25 mg daily 1
• Target blood pressure for elderly patients with hypertension is <140/90 mmHg, though diastolic control remains suboptimal in this case 1
• The 2007 ESH/ESC guidelines emphasize that systolic hypertension is a powerful predictor of adverse outcomes in the elderly, but diastolic pressures should not be ignored 1

Beta-Blocker Optimization

• Metoprolol succinate increase from 25 mg to 50 mg daily is appropriate to address both the elevated diastolic blood pressure and persistent tachycardia (heart rate consistently in 90s) 3
• Metoprolol has demonstrated efficacy in elderly hypertensive patients, with studies showing significant blood pressure reductions in patients aged 50-75 years, with excellent tolerability (94% good/excellent tolerability) 4
• The drug is primarily eliminated by hepatic metabolism, and elderly patients may show slightly higher plasma concentrations, though this is not clinically significant in most cases 3
• Gradual dose titration is recommended in elderly patients given their greater frequency of decreased hepatic, renal, or cardiac function 3

Diuretic Reconsideration

• HCTZ should be discontinued or significantly reduced given the patient's clear history of dehydration-related symptoms (lightheadedness, diaphoresis while cutting firewood, inadequate fluid intake) that resolved when weather changed 2
• The American Geriatrics Society recommends that patients on thiazides should have electrolytes monitored within 1-2 weeks of initiation, with dose increases, and at least yearly to prevent severe hyponatremia 2
• Thiazide-induced hypokalemia is common in elderly patients (occurring in 3-4% of community-dwelling elders) and is associated with increased risk of major adverse cardiovascular events if untreated 5
• If blood pressure control becomes inadequate after HCTZ discontinuation, consider alternative agents such as a calcium channel blocker or ACE inhibitor rather than restarting HCTZ 1

Cardiac Risk Stratification

Mantle Cell Lymphoma-Specific Considerations

• Cardiac assessment with LVEF measurement is required for patients with mantle cell lymphoma treated with curative intent, which this patient has already received 1
• His echocardiogram showing normal LV function (LVEF 50-55%) with grade 1 diastolic dysfunction is reassuring 1
• Hypertension is a critical risk factor for cancer therapeutics-related cardiac dysfunction (CTRCD) in patients treated with anthracycline chemotherapy for malignant lymphoma 6
• Patients with hypertension show significantly higher relative decreases in LVEF after anthracycline chemotherapy (-5.8% vs -1.1% in normotensive patients), with 17% developing CTRCD versus 5% without hypertension 6
• The presence of left ventricular hypertrophy (LVH) further increases risk, making blood pressure control paramount in this population 6

Brukinsa (Zanubrutinib) Cardiac Monitoring

• The patient is on Brukinsa, a BTK inhibitor associated with cardiac arrhythmias, particularly atrial fibrillation 1
• His 7-day event monitor showed no atrial fibrillation/flutter/SVT but did reveal 8% PAC burden, which the metoprolol is appropriately targeting 1
• Continue monitoring for arrhythmias given the known association between BTK inhibitors and cardiac complications 1, 7

Cardiovascular Disease Screening

• Survivors of mantle cell lymphoma with history of mantle irradiation require prospective cardiac screening including resting ECG, stress echocardiogram, and consideration of radionuclide perfusion imaging 1
• Blood pressure management is particularly critical, as every 5 mm Hg decrease in systolic or diastolic blood pressure is associated with a 22% or 26% decrease in likelihood of CAD or valve disease in lymphoma survivors 1
• Lipid screening at 3-year intervals is the most cost-effective strategy for lymphoma survivors 1

Lipid Management

Current Status

• Most recent lipids: total cholesterol 177 mg/dL, triglycerides 180 mg/dL, HDL 55 mg/dL, LDL 86 mg/dL 1
• Previous lipids: total cholesterol 163 mg/dL, triglycerides 202 mg/dL, HDL 56 mg/dL, LDL 67 mg/dL 1
• The patient is statin-intolerant and has no other cardiovascular risk factors besides age 1

Recommendations

• Holding statin therapy is reasonable given statin intolerance and relatively controlled lipid levels (LDL 86 mg/dL, which is below the 115 mg/dL threshold for dyslipidemia per ESH/ESC guidelines) 1
• The 2007 ESH/ESC guidelines define dyslipidemia as LDL-C >3.0 mmol/L (115 mg/dL), which this patient does not meet 1
• Continue lifestyle modifications including low-saturated-fat, low-trans-fat, low-cholesterol diet high in soluble fiber, vegetables, fruits, and whole grains 1
• Encourage 30-60 minutes of moderate-intensity physical activity on most days, which the patient is already achieving with skiing, snow shoveling, and car rebuilding 1

Arrhythmia Management

PAC Burden

• The 8% PAC burden identified on 7-day event monitor is being appropriately treated with metoprolol 1
• Increasing metoprolol to 50 mg daily should further reduce PAC burden 3
• If symptoms of palpitations, lightheadedness, or dizziness persist despite increased beta-blocker dose, electrophysiology consultation is warranted 1

Exercise Tolerance

• The stress test showed appropriate heart rate and blood pressure response but significant decrease in age-predicted exercise tolerance, discontinued due to ankle discomfort and fatigue 1
• No chest pain or EKG changes evident of ischemia during stress protocol 1
• Poor diagnostic value due to decreased exercise tolerance, but reassuring absence of ischemic changes 1
• The patient's subsequent ability to ski, shovel snow, and work in garage without issues suggests functional capacity has improved 1

Follow-Up and Monitoring

Timeline

• Follow-up in 3-4 months rather than 6 months is more appropriate given:
  • Medication adjustment (metoprolol increase)
  • Potential HCTZ discontinuation
  • Persistently elevated diastolic pressures
  • Need to reassess electrolytes after diuretic modification 2

Monitoring Parameters

• Blood pressure monitoring at home should continue, with particular attention to both supine and standing measurements to assess for postural hypotension 1
• Electrolyte monitoring within 1-2 weeks if HCTZ is discontinued or dose-adjusted 2
• Heart rate monitoring to ensure adequate control (target resting heart rate <80 bpm in hypertensive patients) 1
• Annual lipid screening given history of hyperlipidemia and lymphoma survivorship 1
• Periodic cardiac assessment given history of anthracycline exposure and ongoing BTK inhibitor therapy 1

Red Flags Requiring Earlier Follow-Up

• Recurrence of lightheadedness, syncope, or presyncope 1
• New chest pain, pressure, or dyspnea at rest or with exertion 1
• Palpitations or irregular heartbeat 1
• Signs of electrolyte disturbance (muscle weakness, cramping, confusion) 2, 5
• Symptoms of hyponatremia or hypokalemia 2, 5

Special Considerations for Elderly Patients

Age-Related Pharmacokinetics

• Metoprolol elimination half-life may be prolonged in elderly patients (up to 7.2 hours in hepatic impairment), though renal impairment does not significantly affect pharmacokinetics 3
• Initial doses and subsequent titration should be gradual in elderly patients due to greater chance of adverse effects 1, 3
• The geriatric population may show slightly higher plasma concentrations due to decreased metabolism and hepatic blood flow, though this is not clinically significant 3

Comorbidity Management

• The combination of ACE inhibitors with thiazides can cause hyperkalemia, particularly in elderly patients with diabetes, requiring close monitoring of renal function and potassium levels 2
• Blood pressure should always be measured in both supine and erect postures in elderly patients due to increased risk of postural hypotension 1
• Most elderly patients require two or more drugs to control blood pressure, and reductions to <140 mmHg systolic may be particularly difficult to obtain 1

Pitfalls and Caveats

• Do not attribute all symptoms to anxiety or dehydration without excluding cardiac causes, especially in elderly patients with multiple cardiovascular risk factors 8
• Avoid long-term high-dose diuretic therapy in elderly patients prone to dehydration without ensuring adequate fluid intake and electrolyte monitoring 2, 5
• Do not overlook the cumulative cardiac risk from prior anthracycline exposure, ongoing BTK inhibitor therapy, and hypertension 1, 6
• Recognize that poor exercise tolerance on stress testing may limit diagnostic accuracy but does not exclude significant coronary disease 1
• Monitor for bradycardia with beta-blocker dose escalation, particularly in elderly patients 3
• Ensure patient understands the importance of adequate hydration, especially during physical activity, to prevent recurrence of dehydration-related symptoms 2