ORGAN PERFUSION PRESSURE:�A SIGNIFICANT PREDICTOR OF OUTCOMES IN CARDIOGENIC SHOCK

A/Prof. Ta Manh Cuong

Vice – Director of Vietnam Heart Institute

Head of Department for Acute Cardiovascular Care

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BACKGROUND

• Cardiogenic shock (CS) is an ominous condition with a high mortality rate. The diagnosis of CS relies upon signs and/or symptoms of end-organ hypoperfusion.
• However, the combination of hypoperfusion and systemic congestion poses a serious risk and significantly increases mortality rates in critically ill patients.
• Recent study (Altshock-2 ) evaluated organ perfusion pressure (OPP), calculated as mean arterial pressure (MAP) minus central venous pressure (CVP), as a predictor of outcomes in CS¹.

1. European Heart Journal, Volume 45, Issue Supplement_1, October 2024, ehae666.1248, https://doi.org/10.1093/eurheartj/ehae666.1248

CONTENT OF RESEARCH ALTSHOCK-2

• Methods
• All consecutive patients with CS related to acute myocardial infarction (AMI-CS) or acutely decompensated heart failure (ADHF-CS) enrolled in the multicenter Altshock-2 registry between January 2020 and November 2023 were selected.
• Only patients with both OPP and primary endpoint data available were included in the analysis. The primary outcome was in-hospital all-cause mortality.

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RESULTS

• 316 patients (mean age: 64±13 years, 62 [20%] females, mean LVEF: 24% ± 10%, mean MAP: 71±16 mmHg, mean CVP: 12±6 mmHg).
• Mean OPP = 59.1±17.3 mmHg. In-hospital all-cause death: 117 (37%) pts.
• Higher OPP:
• significantly lower risk of in-hospital all-cause death (HR 0.981 per mmHg [95%CI 0.969-0.993], p=0.003) and dichotomized (HR 0.522 [95%CI 0.354-0.770], p=0.001),
• optimal cut-off value of 59.5 mmHg (spe 66.4%, sens 53.8%, AUC 0.61).

RESULTS

• OPP > 59.5 mmHg:
• In ADHF-CS: significantly reduced risk of in-hospital all-cause death (HR 0.315 [95%CI 0.151-0.660], p=0.002),
• but not among AMI-CS patients (HR 0.628 [95%CI 0.392-1.007], p=0.054).
• After multivariable adjustment: higher OPP still predicted significantly lower risk of in-hospital all-cause death (HR 0.984 [95%CI 0.972-0.996], p=0.010).
• In univariable analysis: OPP was also associated with significantly increased long-term overall survival (p-value<0.001), but not with worsening renal function at 24 hours after CS onset, in-hospital length of stay or the composite of left ventricular assist device implantation or heart transplantation.

Eur Heart J, Volume 45, Issue Supplement_1, October 2024, ehae666.1248.

• Conclusions
• In this multicenter, observational, prospective study of patients hospitalized for CS, higher OPP on admission was associated with a significantly reduced risk of in-hospital all-cause death.

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OPTIMAL PERFUSION TARGETS �IN CARDIOGENIC SHOCK

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PHYSICAL EXAMINATION

• The physical examination remains the first indicator of severity of shock.
• Two particularly helpful components: markers of congestion (elevated filling pressures), and markers of perfusion (cardiac output). Limited: majority of data lie in the decompensated heart failure population.
• Recently:elevated biventricular filling pressures (PCWP ≥18 mm Hg and RAP ≥12 mm Hg): significant predictor of in-hospital mortality vs. isolated left-sided congestion or no congestion (in 1,414 patients with CS).
• Right-sided congestion was associated with higher SCAI shock stage and greater in-hospital mortality.

PHYSICAL EXAMINATION

• For the clinician at the bedside:
• elevated JVP
• pulmonary congestion,
• prolonged capillary refill time,
• and “cold extremities”
• particularly useful in the initial assessment.
• Target: clinical euvolemia and a peripheral exam suggestive of warm, well-perfused extremities.

URINE OUTPUT AND RENAL MARKERS

• Acute kidney injury (AKI): abrupt decrease in kidney structure and/or function (15% to 55% of patients with CS).
• 5 types of AKI:
• type 1: abrupt worsening of cardiac function producing renal injury;
• type 2: chronic heart failure progressively eroding renal function and causing chronic kidney disease (CKD);
• type 3: sudden worsening of renal function leading to acute cardiac decompensation;
• type 4: CKD leading to decreased cardiac function/increased risk of cardiovascular events;
• type 5: systemic conditions that result cardiac and renal dysfunction.
• The development of AKI in CS is associated with poor outcomes (long-term dialysis, prolonged hospitalization, both short- and long-term mortality).

• Strategies to protect the kidneys from further insults during CS:
• Renal replacement therapy (RRT)
• RRT in cases: refractory volume overload, marked disruption in acid-base homeostasis, or electrolyte abnormalities
• The goal with continuous RRT: reverse life-threatening biochemical abnormalities and support end-organ function while awaiting renal recovery.
• No specific creatinine or eGFR thresholds established, but decisions RRT initiation should be tailored to individual patients.

MEAN ARTERIAL PRESSURE

• The MAP:
• the average blood pressure during a single cardiac cycle.
• It is equated to the “perfusion pressure” of the organs
• It has been upheld as one of the crucial “targets” of shock resuscitation.
• In CS: MAP target at ≥65 mm Hg.
• Lower MAP may simply be an indicator of more severe illness.

MEAN ARTERIAL PRESSURE (CONT.)

• In patients with CS secondary to decompensated heart failure: better clinical outcomes with an MAP >= 70 mm Hg.
• Initial goal of sBP >90 mm Hg and/or MAP of 55 to 75 mm Hg with concurrent monitoring of perfusion markers may be reasonable.

LV AND RIGHT VENTRICULAR PRESSURES

• LV and right ventricular (RV) filling pressures work on the venous circulation and its role in cardiac output.
• In STEMI: LVEDP >18 mm Hg, sBP to LVEDP ratio of <4, and CPO/Cardiac Power Index are poorer short-term outcomes, including in-hospital mortality.
• Titration of the sBP/LVEDP ratio is much more difficult.
• MCS: has not been definitively established, may be benefit.

LV AND RIGHT VENTRICULAR PRESSURES (CONT.)

• RV parameters of particular interest: PAPi, RAP, RAP/PCWP, and CPA.
• Nonsurvivors pts with AMI-CS + acute decompensated heart failure : higher RAP, RA/PCWP, and lower PAPi and RV stroke.
• RV dysfunction was progressively more severe with escalating SCAI stage.
• Lower CPA in nonsurvivors associated with more severe RV systolic (patients with CS due to primarily LV failure).

CONCLUSIONS

• Cardiology shock is a syndrome of low cardiac output resulting in end-organ dysfunction.
• Higher organ perfusion pressure on admission was associated with a significantly reduced risk of in-hospital all-cause death.
• Clinicians must rely on clinical, biochemical, and hemodynamic parameters to guide resuscitation.
• Several features (physical examination, renal function, serum lactate metabolism, venous oxygen saturation, and hemodynamic markers of right ventricular function), may be useful both as prognostic markers and to guide therapy.

CÂU HỎI LƯỢNG GIÁ

1. Áp lực tưới máu cơ quan:

A – Là hiệu số của huyết áp động mạch trung bình và áp lực tĩnh mạch trung tâm

B – Trong sốc tim, chỉ số tối ưu của áp lực tưới máu cơ quan là >=59,5 mmHg

C – Trong sốc tim, đảm bảo áp lực tưới máu cơ quan tối ưu giúp giảm tỷ lệ tử vong nội viện do mọi nguyên nhân.

D – Tất cả các câu trên đều đúng.

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CÂU HỎI LƯỢNG GIÁ

• 2. Tối ưu hóa áp lực tưới máu cơ quan bằng những mục tiêu:
• A – Đảm bảo đủ thể tích tuần hoàn, ổn định các thông số huyết động trên lâm sàng, tứ chi ấm, tưới máu tốt
• B – Phòng tránh suy thận cấp
• C – Giữ huyết áp động mạch trung bình >= 65 mmHg
• D - Không làm tăng tiền gánh
• E – Tất cả các mục tiêu nói trên

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THANK YOU FOR YOUR ATTENTIONS!