Coefficient of Determination and Slope

A higher $R^2$ indicates a larger proportion of variability in the response explained by the predictor, but does not necessarily imply a steeper slope.

A higher $R^2$ always implies that the slope is large and statistically significant.

The $R^2$ value and the slope estimate are redundant measures of the same relationship.

A lower $R^2$ means the slope must be nearly zero.