Background and Clinical Significance: Heart failure and kidney diseases often coexist and are difficult to clinically manage. Dysfunction in either organ exacerbates dysfunction in the other, potentially leading to cardiorenal syndrome (CRS). CRS has five different subtypes, with CRS type 5 being the most problematic given that it consists of an acute insult superimposed upon chronic CRS. Additionally, type 5 CRS can be complicated by heart failure-related cardiogenic shock (HF-CS), which is associated with increased hospitalizations and has a high 1-year mortality rate. The standard treatment for patients with HF-CS consists of guideline-directed medical therapy for heart failure with reduced ejection fraction (HFrEF) as tolerated, along with inotropic therapies and surgical mechanical left ventricular (LV) support, guided by invasive hemodynamic monitoring. Case Presentation: This case study reports the presentation of a 57-year-old man who presented with type 5 CRS who rapidly decompensated to stage E HF-CS and was effectively and safely treated with aggressive intravenous hydration, a defined plant-based diet (DPBD), and reduction of guideline-directed prescription medications without invasive hemodynamic monitoring. Conclusions: Hydration, a DPBD, and a reduction in medication burden may be effective in CRS. Pilot studies are warranted to evaluate the efficacy of this intervention in CRS in a larger cohort.