Tailored therapy in cardiogenic shock

• Goals: optimize both MAP and CO while ↓ risk of pulmonary edema

MAP = CO × SVR; CO = HR × SV (which depends on preload, afterload, and contractility)

pulmonary edema when PCWP >20–25 (↑ levels may be tolerated in chronic HF/MS)

hepatic and renal congestion (↓ GFR) occur when CVP/RAP >15 mmHg

• Optimize preload = LVEDV ≈ LVEDP ≈ LAP ≈ PCWP (NEJM 1973;289:1263)

goal PCWP ~14–18 in acute MI, 14 in acute decompensated HF

optimize in individual Pt by measuring SV w/ different PCWP to create Starling curve

↑ by giving crystalloid (albumin w/o clinical benefit over NS; PRBC if significant anemia)

↓ by diuresis (qv), ultrafiltration or dialysis if refractory to diuretics or ESRD

• Optimize afterload ≈ wall stress during LV ejection = [(~SBP × radius) / (2 × wall thick.)] and ∴ ∝ MAP and ∝ SVR = (MAP – CVP / CO); goals: MAP >60, SVR 800–1200

MAP >60 (& ∴ SVR ↑): vasodilators (eg, nitroprusside, NTG, ACEI, hydral.) or wean pressors

MAP <60 (& ∴ SVR low/nl, ie, inappropriate vasoplegia): start with inopressor (eg, norepinephrine [α > β], dopamine [β → α w/ ↑ doses], epi [β > α at low doses]); better outcomes w/ norepi than dopa even in cardiogenic shock (NEJM 2010;362:779)

• Optimize contractility ∝ CO for given preload & afterload; goal CI = (CO / BSA) >2.2 if too low despite optimal preload & vasodilators (as MAP permits):

⊕ inotropes: eg, dobutamine (mod inotrope & mild vasodilator) or milrinone (strong inotrope & vasodilator, incl pulm), both proarrhythmic, or epi (strong inotrope & pressor)

mech circulatory support (L/min): IABP (0.5), Impella (3.7–5.5), TandemHeart (5), VAD (L-sided, R-sided or both; temp or perm; 10) or ECMO (6) (JACC 2021;77:1243)