目的:严重右心室或双心室功能障碍患者静脉压长期升高的有害后果是众所周知的,包括肾和肝功能障碍,和体积过载。这些病人唯一的选择,如果他们得不到最佳的治疗,是心脏移植,因为他们不是左心室辅助装置治疗的候选人。平均灌注压(MPP)在高静脉压的危重患者的预后中很重要。出现了一个问题,即MPP对于移植前静脉压升高的患者的心脏移植结果是否重要。射血分数降低的心力衰竭患者的医疗管理涉及在等待移植时使用血管扩张剂降低全身后负荷。我们假设移植前静脉压升高,通过血管舒张显著降低全身动脉弹性(Ea)可显著降低MPP,导致心脏移植后终末器官功能受损,结果不利。这项研究旨在调查低MPP是否成为高静脉压心脏移植受者不良后果的危险因素。
方法:对2012年10月至2020年3月在单一机构接受离体心脏移植的250例心脏移植受者进行了回顾性分析。超过15mmHg的右心房压力(RAP)被认为是高的。此外,Ea计算为收缩末期压力与每搏输出量之比,和MPP计算为平均动脉压和RAP之间的差异在我们的分析中被考虑.移植的结果以90天死亡率和长达7年的生存期来衡量。
结果:如果Ea低(<2.7mmHg/mL,中值)。该组住院死亡率为39.39%,而RAP<15mmHg时为14.49%(p〜0.005)。当Ea很高时,生存率差异不明显:RAP<15mmHg为8%,RAP>15mmHg为4.8%(p~0.550)。这种效应是通过较低的MPP介导的,随着体表面积(BSA)的增加,MPP降低导致的死亡率显着增加。以BSA为指标的MPP(MPPI)与终末期肝病模型评分(r~-0.3580,p<0.0001)以及肌酐(r~-0.3551,p<0.0001)呈负相关。MPPI小于40mmHg/m2与短期生存率较差(MPPI<40mmHg/m2为23.2%,MPPI>40mmHg/m2为7.1%,p~0.001)和中期生存率。即使在中期随访中,高RAP和低Ea对生存率的影响也很明显;高RAP和低Ea在7年随访时仅为30%,而RAP<15mmHg时为75%(p〜0.0033)。
结论:高RAP患者在血管舒张治疗期间的可接受血压需要更高,尤其是那些有较高的BSA。MPPI低于40mmHg/m2是生存的危险因素,在短期和中期,心脏移植后。
OBJECTIVE: The deleterious consequences of chronically elevated venous pressure in patients with profound right ventricular or biventricular dysfunction are well known, including renal and hepatic dysfunction, and volume overload. The only option for these patients, if they fail optimal medical treatment, is a heart transplant, as they are not candidates for left ventricular assist device therapy. Mean perfusion pressure (MPP) is important in the outcomes of critically ill patients with high venous pressure. The question arises whether MPP is important for the outcomes of heart transplants in patients with elevated pre-transplant venous pressure. Medical management of heart failure patients with reduced ejection fraction involves lowering the systemic afterload with vasodilators while awaiting a transplant. We hypothesised that when venous pressure is elevated prior to transplant, a substantial reduction in systemic arterial elastance (Ea) through vasodilation may significantly decrease MPP, resulting in compromised end-organ function and consequent unfavourable outcomes after heart transplantation. This study aims to investigate whether a low MPP serves as a risk factor for adverse outcomes in heart transplant recipients with high venous pressure.
METHODS: A retrospective analysis was conducted on 250 heart transplant recipients undergoing isolated heart transplantation at a single institution from October 2012 to March 2020. Right atrial pressure (RAP) of more than 15 mmHg was considered high. Additionally, Ea calculated as the ratio of end-systolic pressure to stroke volume, and MPP calculated as the difference between mean arterial pressure and RAP were considered in our analysis. The outcomes of transplantation were measured in terms of 90-day mortality and survival up to 7 years.
RESULTS: High RAP was a significant risk factor for short-term and medium-term survival if Ea was low (<2.7 mmHg/mL, the median value). This group had 39.39% in-hospital mortality compared to 14.49% for RAP<15 mmHg (p∼0.005). When Ea was high, this difference in survival was not evident: 8% for RAP<15 mmHg vs 4.8% for RAP>15 mmHg (p∼0.550). This effect was mediated through a lower MPP, and the mortality due to lower MPP increased strikingly with higher body surface area (BSA). A negative correlation was observed between MPP indexed to BSA (MPPI) and the Model for End-Stage Liver Disease score (r∼-0.3580, p<0.0001) as well as creatinine (r∼-0.3551, p<0.0001). MPPI less than 40 mmHg/m2 was associated with poorer short-term (23.2% for MPPI<40 mmHg/m2 vs 7.1% for MPPI>40 mmHg/m2, p∼0.001) and medium-term survival. The impact of high RAP and low Ea on survival was evident even on medium-term follow-up; only 30% survival at 7 years follow-up for high RAP and low Ea vs 75% for RAP<15 mmHg (p∼0.0033).
CONCLUSIONS: The acceptable blood pressure during vasodilator therapy in patients with high RAP needs to be higher, especially in those with higher BSA. MPPI less than 40 mmHg/m2 is a risk factor for survival, in the short and medium-term, after heart transplantation.