Worsening Heart Failure, Hyperkalemia, and a Wide QRS
68-year-old man with HFrEF (LVEF 30%) from ischemic cardiomyopathy is seen 1 week after discharge for decompensated heart failure. He is euvolemic on exam. Medications: sacubitril/valsartan 97/103 mg twice daily, carvedilol 12.5 mg twice daily, spironolactone 25 mg daily, furosemide 40 mg daily. BP 98/62, HR 72, K 5.4 mmol/L, creatinine 1.6 mg/dL (eGFR 38), sodium 134 mmol/L. ECG: sinus rhythm, QRS 164 ms with LBBB, PR 210 ms. He asks about a defibrillator. He has not started an SGLT2 inhibitor. He has had no ventricular arrhythmias.
1. Which guideline-directed medication changes would you make now, and how do you address the hyperkalemia and borderline blood pressure?
Read the worked answer
Do not reflexively stop guideline-directed therapy. He is euvolemic and not in shock; BP 98/62 with HR 72 is low but acceptable if he has no orthostatic symptoms.
- Potassium 5.4 mmol/L: stop potassium supplements and salt substitutes, review diet, and treat with a potassium binder (patiromer or sodium zirconium cyclosilicate) if needed to allow continuation of spironolactone and sacubitril/valsartan. Check potassium and creatinine within 1–2 weeks. If K remains ≥5.5 despite measures, reduce or hold spironolactone; do not stop sacubitril/valsartan solely for mild hyperkalemia.
- Blood pressure: if he is asymptomatic, continue current GDMT. If symptomatic hypotension occurs, reduce the diuretic first; then consider reducing sacubitril/valsartan. Avoid stopping carvedilol unless there is symptomatic bradycardia or shock.
- Add an SGLT2 inhibitor (dapagliflozin or empagliflozin) now. eGFR 38 is acceptable; expect a small reversible creatinine rise. It lowers HF hospitalization and may help hyperkalemia.
- Consider ivabradine if HR remains >70 bpm in sinus rhythm despite maximally tolerated beta-blocker; his HR is 72, so this is borderline.
Device question: He has LVEF 30%, NYHA class II–III symptoms, sinus rhythm, and LBBB with QRS 164 ms. He meets criteria for cardiac resynchronization therapy with a defibrillator (CRT-D), not an ICD alone. However, he was just discharged after decompensation and has not yet had 3 months of optimized GDMT; reassess EF and symptoms after GDMT optimization, then proceed with CRT-D if criteria persist. He does not need a wearable defibrillator unless there is a transient high-risk period.
2. If his systolic blood pressure falls to 88 mmHg after the SGLT2 inhibitor is started, outline a stepwise approach that preserves as much disease-modifying therapy as possible.
Read the worked answer
First assess for symptoms, orthostasis, and volume status. If he is hypovolemic, reduce or hold furosemide; this is the most reversible cause. Check for bleeding, infection, and arrhythmia. If asymptomatic and only a number, continue GDMT and monitor.
If symptomatic: reduce the diuretic first; then reduce sacubitril/valsartan to the previous dose; keep the beta-blocker unless HR <50 or symptomatic bradycardia; continue the SGLT2 inhibitor because it rarely causes hypotension and has a favorable hemodynamic profile. Avoid adding vasodilators. If hypotension persists, consider referral for advanced HF and evaluate for reversible causes. Do not stop all GDMT at once; sequential reduction with reassessment is preferred. If the patient cannot tolerate renin-angiotensin system inhibition, hydralazine/isosorbide dinitrate is an option, especially in Black patients, but it also lowers BP.